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Tool Type	Tools	Description
	2010 Census Briefs Version 2.3i	Census Briefs are short documents that highlight findings from the Ten Year Census and other Census Bureau products. They contain colorful charts to illustrate key findings and cover selected topics such as race, age and sex, household and housing characteristics and older populations to name a few. This list of 2010 Census Briefs was released in September 2012; the list at the link is periodically updated.
	3DFEMWATER and 3DELWASTE	These three dimensional models can be used together to model flow and transport in three dimensional, variably-saturated porous media under transient conditions with multiple distributed and point sources/sinks.
	Acute Exposure Guideline Levels (AEGLs) Chemical Listing	AEGLs are airborne concentrations (expressed as ppm or mg/m3) that represent threshold exposure limits for the general public and are applicable to exposure periods up to 8 hours. There are three AEGL severity levels—AEGL-1, AEGL-2, and AEGL-3—with AEGL-3 being the most severe. From this website, AEGL information can be obtained using chemical name or cas. no. A compilation of AEGLs is also available for download.
	Additional Resources for Citizen Involvement in Source Water Protection	This webpage provides information geared towards private citizens and communities on source water protection, including links to a drinking water pocket guide and a citizen's guide to ground-water protection.
	Administration on Aging: Aging Statistics	The Administration on Aging within the U.S. Department of Health prepares data and statistics for the older and aging U.S. populations. This page was last updated 9/1/2011, and contains data from 2009. This website provides data and statistics for adults aged 65 or older.
	Adult Lead Methodology: Recommendations of the Technical Review Workgroup for Lead for an Approach to Assessing Risks Associated with Adult Exposures to Lead in Soil	The Adult Lead Methodology (ALM) is used for assessing risks associated with nonresidential adult exposures to lead in soil and provides tools for evaluating risks of elevated blood lead concentrations among exposed adults. Special consideration is discussed relative to soil lead intake and blood lead concentrations in women of child-bearing age.
	AERMOD Modeling System	AERMOD can be used to model the movement of chemicals released from one or multiple sources through air; it incorporates air dispersion based on boundary layer turbulence structure and scaling concepts, including treatment of both surface and elevated sources, and both simple and complex terrain.
	Age and Sex Composition in the U.S. Census Briefs	This website provides population estimates and projections by sex, race, and age and includes marital status and median age by gender. A list of current and previous U.S. Census products, data, and information pertaining to women are also available at this website.
	Aggregate Exposures to Phthalates in Humans	This report provides a summary about what is known about human exposures to phthalates and the potential health impacts of exposure to real-world mixtures of these chemicals.
	Aggregated Computational Toxicology Resource (ACToR)	ACToR is an online warehouse of chemical toxicity data. ACToR can be searched using chemical name or cas. no. It provides chemical structure, chemical formula, molecular weight, synonyms, physico-chemical values, in vitro assay data, and in vivo toxicology data. Other EPA chemical toxicity databases that can be searched from this website include ToxRefDB (animal toxicity studies), ToxCastDB (links human disease and exposure to chemicals), and DSSTox (chemical structures and annotations).
	Aging and Sustainability Listserve	The "Aging and Sustainability" Listserve is used by EPA to raise awareness about the susceptibility of older persons to environmental hazards and provide interested parties access to monthly electronic newsletters with information on strategies to reduce or prevent exposure to these hazards. Newsletters also contain information on sustainability and recent research.
	Agricultural Chemical Use Database	USDA’s National Agricultural Statistics Service (NASS) maintains the Agricultural Chemical Use Database. It contains information on commodity acreages and active ingredient (ai) agricultural chemical use (% acres treated, ai/acre/treatment, average number of treatments, ai/acre, total ai used).
	Air and Radiation Program	Information about EPA's Air and Radiation Program can be found at this website.
	Air Emission Sources	This website provides information on air pollution sources of six common air pollutants for which EPA has set standards under the Clean Air Act (carbon monoxide, lead, nitrogen dioxide, ozone, particulate matter, and sulfur dioxide).
	Air Modeling Guidance and Support	The EPA's Air Quality Modeling Group (AQMG) provides leadership to the EPA Regions and State/local/tribal agencies on the selection and use of models in regulatory settings through national modeling guidance. This website provides links to models and guidance.
	Air Monitoring Methods – Criteria Pollutants	This EPA site lists designated reference or equivalent methods for monitoring and measuring ambient concentrations of criteria air pollutants—total suspended particulates (TSP), PM10, PM2.5, PM10–2.5, SO2, O3, CO, NO2, and Pb.
	Air Monitoring Methods – Inorganic (IO) Compendium Methods	This EPA site lists designated reference or equivalent methods for monitoring and measuring ambient concentrations of criteria air pollutants—total suspended particulates (TSP), PM10, PM2.5, PM10–2.5, SO2, O3, CO, NO2, and Pb.
	Air Monitoring Methods – Open Path Monitoring	This EPA site provides an approved method for conducting open-path remote sensing for ambient air concentrations with a Fourier transform infrared spectrometer.
	Air Monitoring Methods – Passive Monitoring	This EPA site provides an approved method for the use of passive monitoring devices to assess personal and environmental exposures to various ambient air toxics.
	Air Pollutants Exposure Model (APEX)	The APEX model can be used to estimate inhalation exposures that may occur at the local level or in specific microenvironments.
	Air Pollution Exposure in European Cities: The EXPOLIS STUDY Exit	The EXPOLIS study measured personal exposure to PM2.5, 30 VOCs, CO, and NO2 in six European cities.
	Air Quality Analysis	This webpage includes information for air quality data analysts inside and outside EPA. The information provided supports EPA's NAAQS Review Process.
	Air Quality System (AQS)	AQS is EPA’s database of ambient air monitoring data for criteria and hazardous air pollutants collected by states and tribes at more than 10,000 monitors across the country.
	Air Toxics Risk Assessment (ATRA) Reference Library Volume 1: Technical Resource Manual	Volume 1 of the Air Toxics Resource Assessment (ATRA) Library series discusses the overall air toxics risk assessment process and includes a discussion of the tiered assessment approach, problem formulation, and variability and uncertainty.
	Air Toxics Risk Assessment (ATRA) Reference Library Volume 2: Facility Specific Assessment	Volume 2 of the Air Toxics Risk Assessment (ATRA) Library series provides tools and procedures that can be used for source-specific or facility-specific risk assessments. This resource includes a description of a tiered approach to risk assessment with examples of models and methodologies given for each iteration in a tiered analysis.
	Air Toxics Risk Assessment (ATRA) Reference Library Volume 3: Community-Scale Assessment	Volume 3 of the Air Toxics Risk Assessment (ATRA) Library series describes approaches to evaluate and reduce air toxics risks posed by emissions from multiple sources at the local level. It includes information on screening level and more detailed analytical approaches. Appendix A to this volume presents several case studies and Appendix B provides an overview of screening-level approaches.
	Air Toxics – Monitoring Methods	This EPA site provides descriptions and methodologies for monitoring and measuring hazardous air pollutants in ambient air.
	Air Trends	This reader-friendly annual report is published by EPA and describes the trends in ambient air concentrations of the criteria air pollutants as well as the emissions of those pollutants from different sources across the country.
	AirData	The AirData site provides access to yearly summaries of U.S. air pollution data, taken from EPA's air pollution databases (AQS). AirData has information about where air pollution comes from (emissions) and how much pollution is in the air outside our homes and work places (monitoring). Reports, visualization tools, and interactive maps are available on the site.
	AIRNow website	AirNow provides air quality information in terms of the Air Quality Index (AQI) for five criteria air pollutants; data on trends as well as real-time indices are available from this collaboration between EPA and other federal, state and local agencies.
	An Alternatives Assessment for the Flame Retardant Decabromodiphenyl Ether (DecaBDE)	This report provides hazard information (human toxicity, ecotoxicity and environmental fate) on flame retardants that were selected for evaluation as potentially functional alternatives to decaBDE.
	America's Children and the Environment (3rd ed.)	This EPA report presents information on environmental stressors that can affect children's health. Information on biomonitoring for several organics, including PFCs, PBDEs, PCBs, phthalates, and BPA as well as lead and mercury are provided. Previous editions of this report published in 2003 and 2000 are also available at this link.
	American Cleaning Institute (ACI) website Exit	The ACI website provides links to useful information on the safe and proper use of cleaning and hygiene products. Resources include tips for clean living, science and policy information, and sustainability.
	American Conference of Governmental Industrial Hygienists (ACGIH) website Exit	ACGIH is an organization made up of industrial hygienists and related professionals with an overall goal of increasing awareness and safety in the realm of occupational and environmental health. Although the organization is best known for developing Threshold Level Values (TLVs), which are exposure limits for chemical substances, ACGIH has also published a wide range of products, including monographs and other reports with information on personal exposure monitoring of airborne chemicals. ACGIH publishes Air Sampling Instruments, a reference book describing the theory, sample strategies, and performance characteristics of instruments commonly used to sample air, including for personal monitoring.
	American FactFinder	FactFinder is a tool that helps users define, search and create datasets that cross reference a number of Census surveys and products.
	American Housing Survey for the United States: 2009 Current Housing Reports	The U.S. Census Bureau administered the American Housing Survey (AHS) to collect information from home occupants, landlords, rental agents, or knowledgeable neighbors to learn about residential characteristics such as unit and lot size, plumbing, condition, heating and cooking fuel types, and the year structures was were built. These data were collected for owner- and renter renter-occupied units, including mobile homes.
	American Housing Survey National Tables	The U.S. Census Bureau administered the American Housing Survey (AHS) to collect information from home occupants, landlords, rental agents, or knowledgeable neighbors to learn about residential characteristics such as unit and lot size, plumbing, condition, heating and cooking fuel types, and the year structures were built. These data were collected for owner- and renter-occupied units, including mobile homes. This website provides a list of select Excel tables from the survey.
	American Time Use Survey	The American Time Use Survey measures the amount of time people spend doing various activities, such as paid work, childcare, volunteering, and socializing.
	Analysis and Products from NHEXAS; National Human Exposure Assessment Survey	This website provides links to NHEXAS work products.
	Analysis of Fat Intake Based on the U.S. Department of Agriculture's 1994-96, 1998 Continuing Survey of Food Intakes By Individuals (CSFII)	This report includes detailed information on dietary habits and the amount of fat present in various types of foods to assess the risk of chemicals that accumulate in fatty tissue. Data include percentiles of fat consumption on the basis of total mass and on a per-unit body-weight basis for 12 food categories and 98 demographic cohorts.
	Analysis of the National Human Activity Pattern (NHAPS) Respondents from a Standpoint of Exposure Assessment Exit	This report provides the percentage of time spent, duration, and frequency of occurrence for selected microenvironments. These data can be broken down by gender, age, time-of-day, day-of-week, season, and U.S. census region using data collect from the National Human Activity Pattern Survey (NHAPS) conducted between 1992 and 1994. NHAPS also collected 24-hour diary data from over 9,000 respondents.
	Analysis of Total Food Intake and Composition of Individual's Diet Based on the U.S. Department of Agriculture's 1994-96, 1998 Continuing Survey of Food Intakes by Individuals (CSFII)	This report includes detailed information on dietary habits of Americans to aid in the identification of potential exposure pathways to hazardous substances. Data include per capita food intake rates for various food items, and has been expanded since the original analysis to include a more comprehensive analysis of food intake.
	Analytical Chemistry Laboratory	EPA's Environmental Science Center at Fort Meade, Maryland provides scientific, laboratory, and technical support through chemical analyses of pesticides and related chemicals. This site includes a link to the National Pesticide Standard Repository and residue analytical methods.
	Analytical Methods and Procedures for Pesticides	This resource provides links to analytical methods and procedures for antimicrobial testing activities and testing for pesticide residues in food, feed, water, and soil.
	Antimicrobial Policy & Guidance Documents	This resource provides information and guidance on antimicrobial pesticides used in consumer products is provided on this website.
	Appendix C – Characterizing Variability and Uncertainty in the Concentration Term. In Risk Assessment Guidance for Superfund (RAGS) Volume III – Part A: Process for Conducting Probabilistic Risk Assessment	This appendix expands upon concepts presented in earlier chapters. It does not provide detailed equations for performing calculations, but instead refers the reader to other Environmental Protection Agency (EPA) guidance documents that provide recommended approaches and calculations.
	Appendix D – Advanced Modeling Approaches for Characterizing Variability and Uncertainty. In Risk Assessment Guidance for Superfund (RAGS) Volume III – Part A: Process for Conducting Probabilistic Risk Assessment	This appendix describes the advanced modeling approaches that can be used in probabilistic risk assessment (PRA) to characterize variability and uncertainty including two-dimensional MCA (2-D MCA), microexposure event analysis (MEE), geospatial statistics, and Bayesian analysis.
	Approaches for the Application of Physiologically Based Pharmacokinetic (PBPK) Models and Supporting Data in Risk Assessment (Final Report)	This report is a resource for EPA scientists and risk assessors on the application and evaluation of PBPK models for risk assessment purposes. Topics covered by this report include the rationale for using PBPK models in risk assessment and the pharmacokinetic data and models needed to derive values; how PBPK models are evaluated; and applications of PBPK model simulations within the current EPA risk assessment framework. A comprehensive reference list current through 2005 is available as an appendix.
	Aquatic Fate Process Data for Organic Priority Pollutants	This resource provides information on fish sampling and analysis strategies and procedures. It also includes information on selection of target species, selection of target analytes, development of human health screening values, sample collection procedures (sample processing, sample preservation, and shipping), sample analysis, and data reporting and analysis.
	AQUATOX Model	This tool is a simulation model that links water quality with aquatic life. It predicts the fate of various pollutants, such as nutrients and organic chemicals, and their effects on the ecosystem, including fish, invertebrates, and aquatic plants.
	ARCS Assessment Guidance Document: Chapter 3 – Program Assessment Guidance	Chapter 3 of the ARCS Program Assessment Guidance Document provides guidance on the collection of sediment samples.
	ARCS Assessment Guidance Document: Chapter 7 – Assessment of Benthic Invertebrate Community Structure	This chapter of the Great Lakes ARCS Program Guidance Document describes methods for collection and data analysis for quantitative benthic invertebrate surveys.
	ARCS Assessment Guidance Document: Chapter 8 – Fish Tumors and Abnormalities	This chapter of the Great Lakes ARCS Program Guidance Document describes methods and materials for fish collection, fish processing, evaluation of tissue samples, and quality assurance and quality control.
	Asbestos Exposure and Cancer Risk. Fact Sheet	This fact sheet from the National Cancer Institute provides information on the uses and health risks associated with exposure to asbestos.
	Asbestos in Air	This document provides a methodology for sampling airborne asbestos fibers.
	Asbestos in the Pacific Northwest and Alaska	This website provides information on EPA's investigation of asbestos in garden vermiculite products.
	Asbestos website	This website provides links to asbestos information, including sources of exposure, asbestos health effects, and asbestos laws and regulations.
	Asbestos: Protect Your Family	This EPA website provides information on vermiculite consumer products that may contain asbestos.
	Asian American & Pacific Islander Initiative Outreach Strategy	This document provides information on outreach activities to Asian American and Pacific Islander populations. Topics covered include seafood consumption, mercury action plan, environmental justice, pesticide hazards, and dry cleaners.
	Assessing Exposure to Pesticides in Food: A User's Guide	This resource is a comprehensive guide to estimating exposure and risk associated with pesticide residues in food. It also provides lists of EPA, USDA, and FDA guidance, policy documents, databases, and other sources of relevant information.
	Assessing Pesticide Cumulative Risk	This resource provides information related to EPA's framework for conducting cumulative risk assessment of pesticides, specifically 5 groups of pesticides—grouped according to common mechanisms of toxicity: organophosphates, n-methyl carbamates, triazines, chloroacetanilides, and pyrethrins/pyrethroids. The website includes links to other resources, including guidance documents and exposure assessment models.
	Assessment Database Version 2 (ADB v.2)	The Assessment Database (ADB) is a tool used by states, territories, tribes and basin commissions to track water quality assessment data, such as attainment of water quality standards and causes and sources of water impairment.
	Assessment of Combined Exposures to Multiple Chemicals Exit	This document reports on a workshop on aggregate/cumulative risk assessment conducted to help develop a framework for the assessment of combined risk from exposure to multiple chemicals. The goal of the workshop was to describe the state of the art in this area of risk assessment and identify next steps.
	An Assessment of Polybrominated Diphenyl Ethers (PBDEs) in Sediments and Bivalves of the U.S. Coastal Zone Exit	This report is the first national assessment of PBDEs in the U.S. coastal zone developed by NOAA's National Status & Trends Program (NS&T).
	ASTM Standards for Monitoring Chemical Hazards in the Workplace Exit	This document describes methods for collecting and measuring chemical hazards in the workplace. Methods include workplace air monitoring and methods for measuring contaminants on workplace surfaces. Standards cover a broad range of chemical hazards including organic and inorganic vapors and metals.
	ATSDR Asbestos Website	This website from CDC provides links and information on hazards associated with exposure to asbestos including information on Libby Asbestos and exposure considerations.
	Australian Exposure Factor Guide	The Australian Exposure Factor Guide is intended to provide guidance recommendations for exposure factor values for risk assessors. Data are arranged by route of exposure and include information on general behavior patterns, physical attributes, anatomical data, and other environmental factors for consideration when developing exposure scenarios. It is a companion to the 2012 update of the enHealth guidance document Environmental health risk assessment: Guidelines for assessing human health risks from environmental hazards.
	AuvTool Exit	The AuvTool is intended to improve the EPA Stochastic Human Exposure Dose Simulation model through the quantification of uncertainty and variability, and fitting statistical distributions to the model.
	Behavioral Risk Factor Surveillance System (BRFSS)	This CDC surveillance program uses a telephone survey to collect state-level data on personal health behaviors among U.S. adult populations that might play a major role in chronic disease morbidity and mortality.
	Benzo(a)pyrene (BaP): TEACH Chemical Summary	This fact sheet is focused on key considerations for children’s exposure assessment produced by U.S. EPA.
	Better Assessment Science Integrating point & Non-point Sources (BASINS) Model	BASINS is a multi-purpose environmental analysis tool designed to integrate geographical information system (GIS), national watershed data, and state-of-the-art environmental assessment and modeling tools.
	Bioaccumulation and Aquatic System Simulator (BASS)	Maintained by EPA’s EPA Center for Exposure Assessment Modeling (CEAM), BASS is a food chain model that simulates population and bioaccumulation dynamics of fish communities. It simulates toxicokinetic, physiological, and ecological processes of fish.
	Bioavailability of Contaminants in Soils and Sediments: Processes, Tools, and Applications Exit	This report provides information on the physical, chemical, and biological factors that may affect the bioavailability of contaminants in soils and sediments.
	Biological Assessment Methods	This resource describes how water quality may be assessed using biological monitoring, for example, assessing the presence and abundance of specific insects (i.e., caddisflies or mayflies).
	Biomarkers Database	Last updated in August 2004 EPA’s Biomarkers Database is an MS Access database that catalogues and evaluates literature related to the usefulness of biomarkers of exposure, susceptibility, and effect. Entries have been created for 5,889 citations (most with abstracts) and also include reviews for relevant citations. A summary report describing the literature search was completed in August 2004. A help guide is available through the database and as a separate PDF file. The accompanying report also reviews up-and-coming techniques and biomarkers in animal models that could be tested for application in human studies.
	Bisphenol A (BPA) Action Plan Summary	This website gives a current summary of the status of EPA's action plan for considering the risks from BPA. This page includes links to previous and current actions by EPA towards rulemaking regarding BPA.
	Bisphenol A Alternatives in Thermal Paper (Revised Final Report)	This report is a draft assessment of 19 chemical alternatives that may substitute for BPA used as a developer in thermal paper.
	Breastfeeding in the United States; Findings from the National Health and Nutrition Examination Surveys, 1999–2006	The results of this survey describe how breastfeeding rates in the United States have changed over time, also considering mother’s age and sociodemographic factors such as race/ethnicity and income levels.
	Breastfeeding Initiatives website Exit	This resource contains links to AAP's breastfeeding recommendations, advocacy materials, and other resources with information in support of breastfeeding.
	Breastfeeding Report Card 2013	This resource provides a state-by-state comparison of how breastfeeding is being protected, promoted, and supported. Indicators include: birth facility support; professional support; mother-to-mother support; state legislation; and availability of public facilities and services.
	Breastfeeding Trends and Updated National Health Objectives for Exclusive Breastfeeding - United States, Birth Years 2000–2004. MMWR 56(30): 760–763	This report describes the results of an analysis of the National Immunization Survey (NIS) data with regard to breastfeeding rates, initiation, duration, and rates for exclusive breastfeeding. The data is summarized by various demographic factors including race, age, marital status, education, and income.
	Breastfeeding website	This website provides information regarding breastfeeding practices in the U.S.
	Brominated and Chlorinated Organic Chemical Compounds Used as Flame Retardants	This resource includes materials for the December 4-5, 2008 Meeting of the California Environmental Contaminant Biomonitoring Program (CECBP) Scientific Guidance Panel (SGP). A brief overview of several BFRs and CFRs is provided.
	Brownfields and Urban Agriculture: Interim Guidelines for Safe Gardening Practices	These guidelines provide information on clean-up and reuse of any brownfield site based on risk assessment and exposure scenarios.
	Building Assessment Survey and Evaluation (BASE) Study	During the five year Building Assessment Survey and Evaluation (BASE) study, EPA collected measurements of indoor air quality in a nationally representative sample of public and commercial office buildings. Survey information about occupant perceptions of air quality is also available along with building specifications such as age and HV/AC characteristics. This site links to the raw data from this study as well as summary statistics and reports published using the data.
	Bureau of Labor Statistics: Summer Youth Labor Force	This resource summarizes employment and unemployment data for U.S. youths. Trends, counts, percentages and employment-population ratios are provided and presented by part- and full-time worker status, race, and sex.
	Bureau of Land Management (BLM) website	This website provides useful information on land resources, including links to BLM state offices.
	Calendex Model	Calendex integrates different pathways (e.g., dietary [food and water] and residential) and routes of exposure (oral, dermal, inhalation) using a calendar-based probabilistic approach. One of the important factors of this approach is that it provides estimates of risk that reflect aggregate and cumulative exposure to discrete individuals, with exposure pathways and routes appropriately linked for the scenarios being assessed. Calendex also allows one to estimate exposure before and after the use of a chemical, as well as during degradation periods. Calendar-based assessments maintain the integrity of the individual by capturing the location of the exposed individual, the time of year in which he or she was exposed, and the patterns of exposure. Calendex also allows for a variety of time-breakout options for the analysis of exposure.
	California Air Toxics Program	The CARB Air Toxics Program institutes the process for identifying and controlling toxic air contaminants related to diesel activities, composite wood products, automobile coatings, residential waste burning, automotive maintenance and repair, dry cleaning, asbestos, ocean-going ship onboard incineration, and chrome plating and anodizing. The program also helps to increase public awareness regarding significant toxic exposures and methods for reducing risk.
	California Population Indoor Exposure Model (CPIEM) Version 2.0 User's Guide	This user’s guide is comprehensive reference document for CPIEM, a Monte Carlo simulation model for estimating inhalation exposure for several indoor microenvironments (plus outdoors). CPIEM employs a mass-balance algorithm to estimate indoor pollutant concentration distributions using airborne concentrations and location/activity profiles.
	CALPUFF Modeling System	CALPUFF is an air dispersion model that simulates long-range transport of pollutants based on the effects of time- and space-varying meteorological conditions on pollution transport, transformation, and removal.
	CalTOX 1.5 Multimedia Risk Assessment Model	The CalTOX Multimedia Risk Assessment model is a spreadsheet-based model for use in health-risk assessments that address contaminated soils and the contamination of adjacent air, surface water, sediments, and ground water. It includes a multimedia and transport transformation model, exposure scenario models, and addresses uncertainty in multimedia multi-pathway models.
	Canadian Domestic Substances List Exit	The Canadian Domestic Substances List (DSL) Program uses a tiered approach to evaluate risk for the 23,000 substances required for consideration under the Canadian Environmental Protection Act (CEPA) of 1999.
	Canadian Health Measures Survey (CHMS) Exit	Begun in 2007, CHMS is a comprehensive set of data (including biomonitoring data) on the exposure of the Canadian population to environmental chemicals.
	The Canadian House Dust Study Exit	The Canadian House Dust Study sampled households between 2007 and 2010 to provide background levels of lead in Canadian homes. This web page provides links to several publications based on the results of the House Dust Study.
	caNanoLab	caNanoLab is a data sharing portal designed to facilitate information sharing in the biomedical nanotechnology research community to expedite and validate the use of nanotechnology in biomedicine. caNanoLab provides support for the annotation of nanomaterials with characterizations resulting from physico-chemical and in vitro assays and the sharing of these characterizations and associated nanotechnology protocols in a secure fashion.
	Carbon Monoxide	This website provides links to various publications related to indoor air quality and consumer products.
	Case Studies in Environmental Medicine (CSEM): Substance-Specific Course Series for Health Professionals	ATSDR has prepared a series of case studies to help health professionals in their evaluation of patients potentially exposed to hazardous substances. Courses have been developed for various inorganics and fibers—such as arsenic, asbestos, beryllium, cadmium, chromium, lead, and nitrate/nitrite—and volatile and semivolatile compounds, including benzene, toluene, tetrachloroethylene, trichloroethylene, PCBs, and PAHs.
	Case Studies in Environmental Medicine Principles of Pediatric Environmental Health	This educational case study document is one in a series of self-instructional modules designed to increase the primary care provider’s knowledge of hazardous substances in the environment and to promote the adoption of medical practices that aid in the evaluation and care of potentially exposed patients. This course focuses on Principles of Pediatric Environmental Health and serves as a companion piece to the Pediatric Exposure History course. The course is available in html or as a downloadable PDF.
	Census Bureau: A Child's Day. Selected Indicators of Child Well-being	This U.S. Census report describes uses various indicators (living arrangements, nativity, family transitions) to portray aspects of children’s well-being. Findings come from interviews conducted in the fall of 2011 for the 2008 Survey of Income and Program Participation (SIPP).
	Census Bureau: Data on Children	Each demographic survey conducted by the U.S. Census Bureau collects different data pertaining to children. Those data, along with a report highlighting the indicators of child well-being are available at this website.
	Census Bureau: Race Data	This U.S. Census Bureau website provides census information by race.
	Center for Exposure Assessment Modeling (CEAM)	EPA’s Center for Exposure Assessment Modeling (CEAM) provides predictive exposure assessment techniques for aquatic, terrestrial, and multimedia pathways for organic chemicals and metals. Links to groundwater, surface water, terrestrial, and multimedia models are found on this website many of which are maintained by CEAM. Links to tools and models for calculating Total Maximum Daily Loads (TMDLs) are also available at this website.
	Chapter 14 – Overview and Getting Started: Planning and Scoping the Multipathway Risk Assessment. In Air Toxics Risk Assessment (ATRA) Reference Library Volume 1: Technical Resource Manual	Chapter 14 provides an overview of multipathway exposure assessment, a discussion of planning and scoping, and tiered multipathway risk assessments. It is included in Part III of Volume I – Human Health Risk Assessment: Multipathway.
	Chapter 15 – Problem Formulation: Multipathway Risk Assessment. In Air Toxics Risk Assessment (ATRA) Reference Library Volume 1: Technical Resource Manual	Chapter 15 discusses the development of the multipathway conceptual model and includes sections on identifying exposure pathways, exposed populations, and endpoints and metrics. It is included in Part III of Volume I – Human Health Risk Assessment: Multipathway.
	Chapter 2 – Occupational Skin Exposure. In OSHA Technical Manual, Section II	This resource is OSHA’s published guidance on accessing dermal exposure to chemicals in the workplace, including monitoring and estimation of absorption.
	Chapter 2 – The Planning, Scoping, and Problem Formulation Phase. In Framework for Cumulative Risk Assessment	Chapter 2 of this report discusses problem formulation in cumulative risk assessments. Sections on planning and scoping, developing the conceptual model, constructing an analysis plan, and lessons learned related to planning and scoping are included.
	Chapter 2 – Preparing for a Risk Assessment and its Risk Characterization – Planning and Scoping. In Risk Characterization Handbook. 2nd ed	This Science Policy Council Handbook describes what a risk characterization is, how to prepare for a risk characterization (planning and scoping), and what the products of a risk characterization are.
	Chapter 2 – Problem Formulation. In Framework for Ecological Risk Assessment	Chapter 2 of this guidance document discusses problem formulation for ecological risk assessments including considerations for selecting measurement endpoints and development of the conceptual model.
	Chapter 2 – Variability and Uncertainty. In Child-Specific Exposure Factors Handbook	This document is intended to provide information on physiological and behavioral factors commonly used in assessing children’s exposure to environmental chemicals, and how children’s exposure differs from adult exposure. Chapter 2 addresses variability and uncertainty.
	Chapter 2 – Variability and Uncertainty. In Exposure Factors Handbook	This chapter provides a discussion of the types of variability and uncertainty and methods for analyzing and presenting variability and uncertainty. A reference list with peer-reviewed literature and relevant government reports is included.
	Chapter 3 – The Design of Risk Assessments. In Science and Decisions: Advancing Risk Assessment Exit	This chapter discusses planning, scoping, and problem formulation. Elements of scope to consider during planning and scoping, methodologic considerations in problem formulation, and major elements of an analysis plan are presented in this chapter.
	Chapter 3 – Elements of a Risk Characterization. In Risk Characterization Handbook. 2nd ed	This Science Policy Council Handbook describes what a risk characterization is, how to prepare for a risk characterization (planning and scoping), and what the products of a risk characterization are. This chapter contains sections on assessing uncertainty and variability.
	Chapter 3 – Lifestage-Specific Problem Formulation. In A Framework for Assessing Health Risks of Environmental Exposures to Children	Chapter 3 of this report discusses problem formulation for lifestage specific risk assessments. This chapter includes sections on planning and scoping to characterize exposures and outcomes during all developmental lifestages, creating a conceptual model, and preparing an analysis plan.
	Chapter 31– Probabilistic Risk Assessment (ATRA). In Risk Assessment and Modeling – Air Toxics Risk Assessment Reference Library: Volume 1 – Technical Resource Manual	Chapter 31 of ATRA Volume I provides an introduction to conducting probabilistic risk assessments. The advantages of this approach, methods, and considerations for presenting the results of a probabilistic risk assessment are presented.
	Chapter 4 – Planning, Scoping, and Problem Formulation for a Multisource Cumulative Assessment. In Air Toxics Risk Assessment (ATRA) Reference Library Volume 3: Community-Scale Assessment	Chapter 4 of this guidance document describes the process of planning, scoping, and problem formulation for a multisource community-scale air assessment including identifying who needs to be involved and the multisource concerns to be evaluated.
	Chapter 4 – Uncertainty and Variability – The Recurring and Recalcitrant Elements of Risk Assessment. In Science and Decisions: Advancing Risk Assessment Exit	This chapter reviews approaches to address uncertainty and variability and comments on whether and how the approaches have been applied to EPA risk assessments. A discussion of how uncertainty and variability are applied to each of the stages of the risk-assessment process and definitions for key terminology related to uncertainty and variability are also addressed in this chapter.
	Chapter 5 – Getting Started: Planning and Scoping the Inhalation Risk Assessment. In Air Toxics Risk Assessment (ATRA) Reference Library Volume 1: Technical Resource Manual	Chapter 5 provides an overview of inhalation exposure assessment and a discussion of planning and scoping, including lessons learned on planning and scoping. It is included in Part II of Volume I – Human Health Risk Assessment: Inhalation.
	Chapter 6 – Assessing Uncertainty. In Guidelines for Exposure Assessment	This document describes the general concepts of exposure assessment and provides guidance on planning and conducting an exposure assessment. Chapter 6 provides information on assessing uncertainty in exposure assessments.
	Chapter 6 – Problem Formulation: Inhalation Risk Assessment. In Air Toxics Risk Assessment (ATRA) Reference Library Volume 1: Technical Resource Manual	Chapter 6 discusses the development of the conceptual model and includes sections on identifying exposure pathways, exposed populations, and endpoints and metrics. It is included in Part II of Volume I – Human Health Risk Assessment: Inhalation.
	Chapter 6: Dietary Exposure Assessment of Chemicals. In Food in Principles and Methods for the Risk Assessment of Chemicals Exit	This resource from the World Health Organization’s International Programme on Chemical Safety (IPCS) discusses how to determine the most appropriate approach for estimating dietary exposure. It lays out a step-wise or tiered approach for assessing exposure that begins with conservative screening methods and then incorporating refinements (e.g., more specific data) as appropriate. Both deterministic and probabilistic approaches are presented.
	Chapter 8 – Interpreting Uncertainty for Human Health Risk Assessment. In Human Health Risk Assessment Protocol	HHRAP describes the evaluation of multi-pathway, site-specific human health risk assessments and was developed for assessment of hazardous waste combustors. See Chapter 8 in HHRAP for a discussion on interpreting uncertainty and limitations in risk assessment process and developing qualitative and quantitative uncertainty estimates.
	Characteristics of Children data	This U.S. Census website compiles child well-being indicators based on data from the 2008 SIPP to characterize activities including TV viewing, eating, playing, spending time with parents; and participating in sports, clubs, lessons, after-school and religious activities as well as academic performance.
	Characteristics of School Buildings in the U.S.	This document (EPA/600/SR-93/218, January 1994) reports on a sampling of 100 schools identified from the 1994 EPA National School Radon Survey that were further evaluated to obtain additional information (e.g., age, size, HVAC systems, proximity to power lines).
	Chemical and Product Categories (CPCat) Database	The CPCat database contains use and product information. Users can search for chemicals by chemical name or CASRN. All of the information is from publicly accessible sources.
	Chemical Data Access Tool (CDAT)	CDAT is a compilation of health and safety information submitted to EPA under the Toxic Substances Control Act (TSCA). This information is intended for individuals interested in learning more about chemicals that are manufactured in or imported into the United States, and the tool allows access to recently declassified (i.e., November 2011) and newly available health and safety studies. Information stored in eDoc, TSCATS, HPVIS, and the 8(e) Voluntary Declassification Program is also accessible through CDAT.
	Chemical Data Reporting (CDR)	CDR data are a collection of screening-level, exposure-related information on chemical substances. The CDR rule requires manufacturers and importers to submit information on the production and use of chemicals in commerce in large quantities. The CDR data constitute the most comprehensive source of basic screening-level, exposure-related information on chemicals available to EPA and include the following information when available: production volume, maximum concentration and physical form(s), total number of manufacturing, processing and use sites, total number of reasonably likely to be exposed manufacturing and industrial workers, and industrial processing and use and commercial and consumer use data.
	Chemical Hazard Reviews Volume 1: Environmental Profiles of Chemical Flame-Retardant Alternatives for Low-Density Polyurethane Foam	This resource provides a description of the general characteristics of flame retardants, a general overview of exposure pathways and routes for flame retardants used in flexible polyurethane foam and the results of the assessments of 14 formulations of flame-retardant products most likely to replace commercially available pentabromodiphenyl ether (pentaBDE).
	Chemical Hazard Reviews Volume 2: Environmental Profiles of Chemical Flame-Retardant Alternatives for Low-Density Polyurethane Foam	This resource provides detailed hazard reviews of available information for each of the chemicals in the 14 flame-retardant formulations evaluated through the Furniture Flame Retardancy Partnership.
	Chemical Property Values	This webpage provides information that might be useful for predicting partitioning of chemicals between environmental media that has been consolidated by EPA’s Ecosystem Research in Athens, GA. Identifies sources for measured chemical property values and methods for estimating values.
	Chemical Safety Information from Intergovernmental Organizations (INCHEM) Exit	A tool created through cooperation between the International Programme on Chemical Safety (IPCS) and the Canadian Centre for Occupational Health and Safety (CCOHS), INCHEM provides public access to peer-reviewed publications on chemical risks/safety and the sound management of chemicals. Specifically, INCHEM provides access to the following types of information: Concise International Chemical Assessment Documents (CICADS); Environmental Health Criteria (EHC) monographs; Harmonization Project publications; Health and Safety Guides (HSGs); International Agency for Research on Cancer (IARC) summaries and evaluations; International Chemical Safety Cards (ICSCs); Joint Expert Committee on Food Additives (JECFA) monographs and evaluations; Joint Meeting on Pesticide Residues (JMPR) monographs and evaluations; Pesticide Data Sheets (PDSs); among others.
	Chemical Screening Tool For Exposures and Environmental Releases (ChemSTEER)	ChemSTEER is used to estimate inhalation and dermal exposures to chemicals during chemical use and manufacture. Estimates also cover the releases of a chemical into the air, water, and land associated with occupational use.
	Chemicals under the Toxic Substances Control Act (TSCA)	This site can be used to get information on chemicals and their regulation under TSCA; ways to prevent and reduce pollution; and safer chemicals, products, and practices.
	Child-Specific Exposure Factors Handbook	The Child-Specific Exposure Factors Handbook provides information on various physiological and behavioral factors commonly used in assessing children’s exposure to environmental chemicals and also contains population data for selected factors.
	Child-Specific Exposure Scenarios Examples	The Child-Specific Exposure Scenarios Examples provides common exposure pathways and tools for estimating exposure, dose, and adverse health effects in children. The scenarios provided in the document use data found in EPA’s Child-Specific Exposure Factors Handbook and the Exposures Factors Handbook: 2011 Edition.
	Chromium in Drinking Water	This resource provides basic information about chromium, a discussion of drinking water standards for chromium, and important distinctions between total chromium, trivalent chromium, and hexavalent chromium.
	Clean Air Status and Trends Network (CASTNET) Data	CASTNET provides access to measured concentrations of criteria air pollutants from various rural monitoring sites around the United States; data can be used to assess trends in air quality, ecological effects, and atmospheric deposition.
	Cleaning up Superfund Sites	This website provides specific information related to site cleanup at each phase of the process. Links related to site assessment, National Priorities List, remedial investigation/feasibility study, remedy decisions, remedial design/remedial action, post construction, deletion, and reuse are provided.
	Clean Water Act Analytical Methods	Under the authority of the Clean Water Act (CWA) (CFR Title 40 Part 136), EPA publishes laboratory analytical methods that are used by industries and municipalities to analyze the chemical, physical and biological components of wastewater and other environmental samples.
	Climate Leaders Greenhouse Gas Inventory Protocol Core Module Guidance: Direct HFC and PFC Emissions from Use of Refrigeration and Air Conditioning Equipment	This report provides guidance on estimating direct HFC and PFC emissions from the use of air refrigeration and air conditioning equipment. The guidance addresses household, commercial and industrial refrigeration and air conditioning, as well as fixed and portable fire suppression equipment.
	CLU-IN website Exit	The “Technologies: Characterization and Monitoring” portion of the Contaminated Site Cleanup Information (CLU-IN) website provides technology profiles for common field analytical methods for water and soil/sediment.
	Coastline Population Trends in the United States: 1960 to 2008	This report provides a summary of the populations living in coastal areas. Additional information for coastal populations (i.e. proximity of housing to water bodies) can be found in the Census Statistical Abstracts and the American Housing Survey.
	Community Air Screening How-To Manual, A Step-by-Step Guide to Using Risk-Based Screening to Identify Priorities for Improving Outdoor Air Quality	This document presents a step-by-step guide for communities to conducting a cumulative risk assessment focused on emissions of pollutants to air as part of EPA’s Community Action for a Renewed Environment (CARE) program.
	Community Multiscale Air Quality (CMAQ)	CMAQ is an air quality model and software suite designed to model multiple pollutants at multiple scales (from urban to regional). CMAQ can model tropospheric ozone, fine particles, toxics, acid deposition, and visibility degradation. It allows regulatory agencies to evaluate the impact of air quality management decisions and gives scientists the ability to probe, simulate, and understand chemical and physical interactions in the atmosphere.
	Community-Focused Exposure and Risk Screening Tool (C-FERST)	EPA developed C-FERST as a “one-stop-shop community mapping and assessment tool” that assessors can use when conducting multimedia community assessments. The tool is a web-based geographic information system (GIS) and information resource to be used to characterize cumulative risk from chemical and non-chemical stressors and identify communities affected by these stressors. C-FERST was developed to help assess disproportionate impacts in communities and serve as a tool in environmental justice efforts.
	Commuting Data (Journey to Work)	This website provides commuting data such as travel time and distance to and from work, public transportation use, and transportation expenses.
	Compendium of Methods for the Determination of Air Pollutants in Indoor Air	This 1990 EPA publication provides information on monitoring and laboratory analysis techniques for indoor air pollutants including nitrogen dioxide, formaldehyde, PAHs, VOCs, carbon monoxide, and PM.
	Comprehensive Air Quality Model with Extensions (CAMx) Exit	The CAMx model allows for the assessment of gaseous and particulate air pollution (i.e., ozone, PM2.5, PM10, air toxics) over many scales ranging from sub-urban to continental. It also enables examination of source attribution.
	Comprehensive Environmental Assessment and U.S. EPA Nanomaterial Case Studies. Presented at NATO Workshop, Faro, Portugal, April 27–30, 2008	EPA presented at NATO Workshop in Faro, Portugal, April 27 - 30, 2008, about how EPA is using the CEA approach to assess potential risks associated with nanomaterial.
	Comprehensive Environmental Assessment Applied to Multiwalled Carbon Nanotube Flame-Retardant Coatings in Upholstery Textiles: A Case Study Presenting Priority Research Gaps for Future Risk Assessments (Final Report)	This case study report compares multiwalled carbon nanotubes (MWCNTs) and a non-nano-enabled product-decabromodiphenyl ether (decaBDE)-as flame-retardant coatings applied to upholstery textiles, and provides a characterization and comparison related the following: historical and current applications; product life cycle; fate, transformation, and transport in environmental media; exposure and dose; human health and ecological effects; and research needs.
	Comprehensive Environmental Response, Compensation, and Liability Information System (CERCLIS) Search	The CERCLIS Search allows you to retrieve Superfund data from the Comprehensive Environmental Response, Compensation, and Liability Information System (CERCLIS) database in Envirofacts. Users can specify a facility by using any combination of facility name and geographic location.
	Concepts, Methods, and Data Sources for Cumulative Health Risk Assessment of Multiple Chemicals, Exposures and Effects: A Resource Document	This resource provides concepts, methods, and data sources for conducting cumulative risk assessments for populations exposed to multiple chemicals, considering multiple exposure routes and multiple health endpoints. This document also address complications associated with evaluating multiple chemicals, such as toxicological interactions and environmental transformations of the chemical components.
	ConsExpo 5.0 Model Exit	ConsExpo is a set of models that can be used to estimate and assess human exposure to substances from consumer products used indoors. This model is primarily used in the European Union’s assessment of industrial chemicals (REACH).
	Consolidated Human Activity Database (CHAD)	EPA’s Consolidated Human Activities Database is a searchable tool for accessing the detailed diaries of daily behavior from 19 separate studies, including the National Human Activity Pattern Survey (NHAPS). There are over 30,000 individual day entries broken down by activity type and hour.
	Consulting With Indian Tribal Governments at Superfund Sites: A Beginner's Booklet Exit	This document provides the basics of government-to-government consultation with Indian tribal governments within the context of Superfund.
	Consumer Expenditure Survey	The Consumer Expenditure Survey (CE) is a Federal survey that provides information on the complete range of consumer expenditures and incomes as well as the characteristics of those consumers.
	Consumer Product Information Database (CPID) Exit	The CPID contains health effects information for nine categories of products used in the home and in some commercial/institutional settings that contain chemicals. The databases links brand names to health effects and provides label information, including brand name, ingredients and warnings, manufacturer information, health effect information, and properties and health studies for the chemical ingredients of brands.
	Consumer Product Ingredient Safety: Exposure and Risk Screening Methods for Consumer Product Ingredients 2nd Edition. Washington, DC. Exit	This resource is intended as a guide for companies engaged in stewardship of consumer products with repeated human exposures or environmental releases, especially from down-the-drain disposal. The document includes several examples of exposure to high production volume (HPV) chemicals via consumer products. The second edition contains updated information on exposure assessment methodology as well as finalized case studies presented in the 2005 edition published by the Soap and Detergent Association (SDA; now the American Cleaning Institute).
	Consumer Products Treated with Pesticides	Consumer Products Treated with Pesticides describes the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), which requires the registration of any substance intended to prevent, destroy, repel, or mitigate pests. The Code of Federal Regulations, which prescribes the conditions under which an exemption from registration is allowed, is also described along with EPA's pesticide registration number, example exemption statements, and enforcement.
	Contaminated Sediment in the Great Lakes	Contaminated sediments are a significant problem in the Great Lakes basin. This webpage explains the assessment approach, causes of contaminated sediment, sediment remediation strategies, and the delisting and recovery process.
	Contaminated Sediment Management Strategy	EPA’s Office of Water developed the Contaminated Sediment Management Strategy to provide a framework for the assessment, prevention, remediation, management of dredged material, research, and outreach regarding sediment contamination. In particular, chapter 5 of the strategy provides a strategy for assessing sediment contamination.
	Contaminated Sediment Remediation Guidance for Hazardous Waste Sites	EPA’s Office of Superfund Remediation and Technology Innovation (OSRTI) developed a technical and policy guidance document for project managers and management teams for remedial actions at sediment contaminated sites.
	Continuing Survey of Food Intake by Individuals (CSFII) 1994–96, 1998 CD-ROM	This dataset includes information from all individuals who participated in the Continuing Survey of Food Intakes by Individuals (CSFII) in 1994-96 and 1998 and the Diet and Health Knowledge Survey (DHKS) in 1994-96. This release also includes the Technical Support Databases for CSFII 1994-96, 1998 (food codes, nutrient values, and recipes).
	Control of Nanoscale Materials under the Toxic Substances Control Act	EPA provides information related to development of a comprehensive approach for regulating nanoscale materials under the Toxic Substances Control Act (TSCA). Specifically, EPA describes the Significant New Use Rule (SNUR), Information Gathering Rule, Test Rule, and other regulations for addressing potential risks associated with nanomaterials.
	Cooperative Fish Tissue Monitoring Program; Sport Fish Tissue Consumption Advisory Program	This document provides a list of fish consumption advisory chemicals and fillet upper-bound limit concentrations and advisory meal consumption rates; fish tissue and sediment reporting limits; and median lipid levels by species, 1998-2006.
	Council for Regulatory Environmental Modeling (CREM)	The CREM is a cross-agency group which promotes scientific integrity and defensibility in the modeling principles, practices, and guidance which inform environmental and public health regulatory decision-making and research applications. Multiple links are available at this website.
	The Critical Role of House Dust in Understanding the Hazards Posed by Contaminated Soils. International Journal of Toxicology 16: 339-362	This article suggests that contaminants are found in higher concentrations in house dust and that fine particles are more bioavailable, indicating that ingestion of contaminants in soil via house dust is an important exposure pathway.
	Cumulative and Aggregate Risk Evaluation System (CARES) Exit	According to this website, "CARES® (Cumulative and Aggregate Risk Evaluation System) was originally developed in 2001 as a population, calendar-based, probabilistic model for estimating aggregate and cumulative exposure and risk across multiple routes: food, water, and residential for pesticides. The model is undergoing significant upgrades to meet current and future needs . . ."
	Current Intelligence Bulletin 65: Occupational Exposure to Carbon Nanotubes and Nanofibers	In this Current Intelligence Bulletin, NIOSH provides the best available scientific information to assess potential hazards and risks and to provide guidance for protecting workers from risks associated with carbon nanotubes (CNTs) and nanofibers (CNFs).
	D6178: Standard Practice for Estimation of Short-term Inhalation Exposure to Volatile Organic Chemicals Emitted from Bedding Sets Exit	This document describes procedures for estimating human inhalation exposure to volatile compounds emitted from bedding sets for the purpose of characterizing health risks due to short-term VOC exposures. Exposure estimates for specific raw materials and other components of different bedding sets could be evaluated and compared.
	Database of Sources of Environmental Releases of Dioxin-Like Compounds in the United States	This resource is a repository of specific CDD/CDF emissions data from all known sources in the United States. The database information can be analyzed to track emissions of CDD/CDF over time, compare specific profiles between and among source categories, and develop source specific emission factors that can then be used to develop emission estimates.
	Data Finder: Life Stages and Populations	This tool is a repository of downloadable data sources. Life stage/population data are available related to children’s health (Toxicity and Exposure Assessment for Children's Health [TEACH] Database); senior health (Physiological Parameters Database for Older Adults); and worker health (Toxic Substances Control Act Test Submissions 2.0 [TSCATS 2.0]).
	Data Sources Available for Modeling Environmental Exposures in the Older Adult Population	This report contains the same type of information found in EPA‘s Exposure Factors Handbook, but with older adults as the sole population subgroup of interest.
	Defining Uncertainty and Variability in Environmental Fate Models Exit	This report from the Canadian Environmental Modelling Centre identifies model equations and descriptive parameters as the main components of chemical fate in the environment mass balance models and discusses the relative importance of data input to model accuracy. The report discusses defining uncertainty, variability, difference, and error in the framework of model reliability.
	Dermal Absorption of Environmental Contaminants from Soil and Sediment: A Critical Review. Journal of Exposure Science and Environmental Epidemiology 19: 119–148	This study is a characterization of the dermal availability of chemical contaminants in soil and/or sediment to inform risk assessment of hazardous wastes sites.
	Dermal Exposure Assessment: A Summary of EPA Approaches	This report describes the different approaches used to conduct dermal exposure assessment in the Agency and identifies areas where approaches might be harmonized to exchange information and to share methods and data to improve the transparency of dermal exposure assessments in the Agency.
	Descriptive Statistics Tables from a Detailed Analysis of the National Human Activity Pattern Survey (NHAPS) Data	This report presents detailed results tables from an unweighted statistical analysis of selected portions of the 1992-94 National Human Activity Pattern Survey (NHAPS) data base. NHAPS was designed to collect data on the potential exposure of the American people to important household pollutants. As part of the data-collection methodology, randomly selected individuals were asked to supply both minute-by-minute diaries spanning an entire day and answers to a wide range of follow-up questions focused on specific exposure types.
	Design for the Environment (DfE) Program	EPA's DfE program helps consumers, businesses, and institutional buyers identify cleaning and other products that perform well, are cost-effective, and are safer for the environment.
	Detailed Fact Sheet: Architectural Coating Rule for Volatile Organic Compounds	This report describes the 1998 rule under the Clean Air Act that limits the amount of volatile organic compounds (VOC) that manufacturers and importers of architectural coatings can put into their products.
	Development and Validation of Bioaccumulation Models for Small Mammals	This report assembles a database of soil and small mammal contaminant concentration data from published literature for a number of contaminants, develops uptake factors (UFs) and other bioaccumulation models from these data, and evaluates the accuracy of the estimates using independent data not used in model development. A database of soil and whole-body small mammal concentrations for nine inorganics was developed for use in evaluating risks to predatory wildlife.
	Development of a Relative Potency Factor (RPF) Approach for Polycyclic Aromatic Hydrocarbon (PAH) Mixtures	This draft document provides a methodology for estimating cancer risk from exposure to PAH mixtures by summing doses of component PAHs after scaling the doses (with RPFs) using benzo[a]pyrene as the index PAH.
	DFLOW Model	DFLOW is a tool developed to estimate design stream flows for low flow analysis and water quality standards.
	Dietary Guidelines for Americans	USDA Dietary Guidelines for Americans provides recommendations for the general population and specific population groups (e.g., pregnant women) for choosing a healthy diet.
	Dioxin website	This EPA-wide dioxin portal provides summary information on dioxins and includes links to past EPA documents, including health assessments, workshops, studies, and surveys of sources.
	Dioxins and their Effects on Human Health Fact Sheet Exit	This fact sheet from WHO provides information on sources of dioxin, sensitive subgroups, and WHO activities related to dioxin.
	Discharge Monitoring Report (DMR) Pollutant Loading Tool	EPA has released a Discharge Monitoring Report (DMR) Pollutant Loading Tool designed to assist in locating discharges, identifying pollutants and amounts being discharged.
	Distributed Structure-Searchable Toxicity (DSSTox) Database Network	Developed by EPA's National Center for Computational Toxicology (NCCT), the DSSTox database provides users the opportunity for publishing chemical toxicity data files that contain chemical structure and toxicity information. DSSTox files can be searched using chemical name, cas. no., or chemical formula or by chemical structure (SMILES string or by drawing using Java Molecular Editor [JME]).
	Dose Calculator	This is a computer program that allows users to calculate the dose of a toxic substance to which an individual may be exposed. The user can select from four scenarios: air, soil, water, or fish consumption and define exposure parameters. It calculates cancer risk and compares to ATSDR and EPA reference values.
	Draft Global Non-CO2 Emissions Projections Report: 1990-2030	The 2011 draft report provides estimated projections to 2030 for emissions from more than twenty emissions sources. The gases included in this report are methane, nitrous oxide, and fluorinated greenhouse gases (hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride).
	Draft Guidance for Industry: Safety of Nanomaterials in Cosmetic Products	This document describes key points to consider in assessing the safety of nanomaterials in cosmetic products, including aspects of chemical properties, impurities, exposure routes, uptake, and adsorption. It contains nonbinding recommendations that, when finalized, will represent the FDA’s current thinking on the topic of safety of nanomaterials in cosmetic products.
	Draft Protocol for Measuring Children’s Non-Occupational Exposure to Pesticides by all Relevant Pathways	The goal of this document is to provide guidance for generating data that can be used to improve exposure assessments for young children, including approaches and methods for conducting field studies to collect exposure measurement data and to develop exposure factors.
	Draft WHO/IPCS Framework for Risk Assessment of Combined Exposures to Multiple Chemicals Exit	This website contains a description of the draft WHO/IPCS Framework for Risk Assessment of Combined Exposures to Multiple Chemicals, which is a document that describes a framework for the assessment of combined risk from exposure to multiple chemicals. The frameworks for exposure and hazard assessments are presented as tiers—from simple (Tier 0) to more refined (Tier 3). This document is supplemented by two case studies that apply the frameworks—one case study on polybrominated diphenyl ethers (PBDEs) and the other on carbamates.
	Drinking Water Analytical Methods	This site contains a list of all the currently EPA-approved methods for analyzing drinking water to demonstrate compliance with current regulations.
	Drinking Water Contaminants: National Primary Drinking Water Regulations	This resource provides links to information about National Primary Drinking Water Regulations, including contaminants and maximum contaminant levels.
	Drinking Water Contaminants: Perchlorate	This resource provides a review of perchlorate as a drinking water contaminant and a discussion of the regulatory history leading to EPA's decision to regulate perchlorate under the Safe Drinking Water Act (SDWA).
	Drinking Water from Household Wells	This report provides general information about drinking water from private drinking water sources, including sources of pollution. It further describes types of activities that can negatively impact a private water supply, problems to look for, and how to protect a water supply. A list of informational sources is also provided.
	Drinking Water Standard for Arsenic Fact Sheet	This webpage describes potential health effects from exposure to arsenic in drinking water, an overview of the Final Rule for Arsenic in Drinking Water, and background information on the natural occurrence of arsenic.
	Drinking Water Treatability Database (TDB)	The Drinking Water Treatability Database is a tool that provides information on treatment processes for more than 25 water treatment processes used by drinking water utilities for contaminants.
	Dust Control Handbook for Minerals Processing	This handbook provides information related to dust formation and dust control, dust control systems, testing dust control systems, sampling dust in mines, collecting and disposing of dust, and personal dust protection.
	Dynamic Maps, GIS Data, and Analysis Tools	The National Renewable Energy Laboratory (NREL) provides maps, GIS data, and analytical tools to show geographical displays and locations for renewable energy sources such as biomass, solar, geothermal, hydrogen and wind.
	eChemPortal Exit	eChemPortal provides free public access to information on physical chemical properties, ecotoxicity, environmental fate and behavior, and toxicity of chemicals. It allows users to search reports and datasets by chemical name, number, or property and also provides chemical exposure and use information.
	Ecological Risk Analysis	This web page from Oak Ridge National Laboratory (ORNL) provides links to various guidance documents, tools, and applications for conducting ecological risk analysis.
	Ecological Screening Assessment Report on Polybrominated Diphenyl Ethers (PBDEs) Exit	This assessment report provides information on the use and sources, fate, exposure, and effects of PBDEs.
	Ecological Screening Assessment Report: Perfluorooctane Sulfonate (PFOS) Exit	This assessment report provides information on the use and sources, fate, exposure, and effects of PFOS.
	Ecological Structure Activity Relationships (ECOSAR)	ECOSAR is a computerized program that uses structure activity relationships to predict acute and chronic toxicity to aquatic organisms such as fish, aquatic invertebrates, and aquatic plants.
	Ecotoxicology Database (ECOTOX)	ECOTOX is a source for locating single chemical toxicity data for aquatic and terrestrial plants and wildlife. The database combines information from three databases: AQUIRE, PHYTOTOX, and TERRETOX. ECOTOX can be searched for aquatic or terrestrial data using one or more of the following parameters: chemical (name or CAS no.), taxonomy (e.g., species name), test results (e.g., endpoint), and various test conditions (e.g., field test, freshwater, diet).
	ED Data Express website	This resource from the U.S. Department of Education can be used to locate data on student demographics, academic performance, and graduation rates across the U.S. It also provides statistics for homeless and migrant students, public and non-public schools.
	The Effects of Great Lakes Contaminants on Human Health; Report to Congress	This report summarizes existing literature on Great Lakes human health studies related to contaminants, as well as research progress made by ATSDR’s Great Lakes Human Health Effects Program during FY 1992.
	Effluent Guidelines: Industrial Regulation	This resource provides information on existing industrial regulations, regulations under development, and links to relevant publications for effluent guidelines.
	Effluent Limitation Guidelines	Effluent guidelines are national standards, based on the performance of treatment and control technologies, for wastewater discharges to surface waters and municipal sewage treatment plants. EPA issues effluent guidelines for categories of existing and new sources.
	Elemental Analysis Manual (EAM) for Food and Related Products	The EAM compiles current published analytical methods and procedures used by FDA analysts to standardize elemental analysis in FDA laboratories.
	Eliminating Childhood Lead Poisoning: A Federal Strategy Targeting Lead Paint Hazards	This document discusses the issue of lead poisoning in children and provides recommendations for eliminating lead poisoning. Data on the use of lead paint, lead painted surfaces, and the number of dwellings containing lead paint in homes (by years) are also provided.
	Emission & Generation Resource Integrated Database (eGRID)	eGRID contains data on the environmental characteristics of almost all U.S.-based generated power. Characteristics recorded include air emissions for nitrogen oxides, sulfur dioxide, and other emissions as well as net generation, emission rates, and other attributes.
	Emission Factor and Emission Estimation Tools	This webpage provides links to emission factor tools (WebFIRE) for criteria and hazardous air pollutants and emission estimation tools (documents and software) for organics and other air pollutants. Software links include: TANKS, SPECIATE, LandGEM, and WATER9.
	Emission Standards for Volatile Organic Compounds (VOCs) in Consumer Products	EPA promulgated national volatile organic compound (VOC) emission standards for certain categories of consumer products pursuant to section 183(e) of the Clean Air Act (Act). Information on these standards can be found at this website.
	Emissions Factors & AP 42, Compilation of Air Pollutant Emission Factors	Emission factors are fundamental tools used in developing inventories of air pollutant sources. EPA’s AP-42 provides emission factors for various source categories (i.e., industry sectors or groups of similarly emitting sources).
	Empirical Models for the Uptake of Inorganic Chemicals from Soil by Plants	This document provides regression models and uptake factors for use in estimating the uptake of inorganic elements by above-ground plant tissues.
	Enforcement and Compliance History Online (ECHO)	EPA’s Enforcement and Compliance History Online website is used to search for local facilities to access their compliance with environmental regulations. Searches can provide pollution sources, enforcement-related maps, and your state’s performance.
	Ensuring Risk Reduction in Communities with Multiple Stressors: Environmental Justice and Cumulative Risks/Impacts	This document provides NEJAC’s recommendations on short-term and long-term actions EPA should take to implement the concepts contained in its Framework for Cumulative Risk Assessment to ensure environmental justice for all communities and tribes.
	Envirofacts	Envirofacts is a single point of access to several EPA databases with information about environmental activities that may affect air, water, and land anywhere in the United States. Envirofacts can be used to learn more about environmental activities in an area or to generate maps of environmental information. The Multisystem Search Form allows users to search multiple environmental databases at one time for facility information, including toxic chemical releases, water discharge permit compliance, hazardous waste handling processes, Superfund status, and air emission estimates.
	Environmental and Workplace Health: Vulnerable Populations Exit	This resource provides links to information and regulatory initiatives surrounding environmental contaminant exposure by children and pregnant women, aboriginals, and older adults.
	Environmental Chemistry Methods (ECM)	This EPA website describes environmental chemistry methods (ECMs) for soil and water used to determine the fate of pesticides in the environment. ECMs are listed by analyte and include matrix, method date, registrant, analysis, and limit of quantitation (LOQ) for each; EPA reviews of the methods are also provided, if available.
	Environmental Fluid Dynamics Codes (EFDC)	The Environmental Fluid Dynamics Code (EFDC) is a state-of-the-art 1D, 2D, or 3D hydrodynamic model that incorporates hydrodynamic, sediment-contaminant, and eutrophication components.
	Environmental Health Criteria 229: Selected Nitro- And Nitrooxy- Polycyclic Aromatic Hydrocarbons Exit	This IPCS document provides information on the relationship between exposure to environmental pollutants and human health and guidelines for setting exposure limits.
	Environmental Health Criteria 237: Principles for Evaluating Health Risks in Children Associated With Exposure to Chemicals Exit	This document provides a systematic analysis of the scientific principles to be considered in assessing health risks in children from exposures to environmental agents during distinct stages of development.
	Environmental Health Risk Assessment: Guidelines for Assessing Human Health Risks from Environmental Hazards Exit	This guidance document provides information on basic concepts in environmental health risk assessment, including problem formulation, tiered approaches to exposure assessment. Specific guidance is provided for several topics related to exposure assessment including: assessing exposure from multiple routes and sources of exposure, probabilistic exposure modelling, and biomonitoring.
	Environmental Justice Screening and Mapping (EJSCREEN) Tool	This website provides access to the EJView mapping tool that allows users to create maps and generate detailed reports based on user-defined geographic areas and data sets. EJView includes demographic, health, environmental and facility-level data that may affect public and environmental health within a community or region.
	Environmental Justice website	This EPA website provides links and information related to environmental justice issues, including information links for the National Environmental Justice Advisory Council (NEJAC), Plan EJ 2014, and the Federal Interagency Working Group on Environmental Justice (IWG).
	Environmental Measurement: Collection of Methods	This website provides access to a wide variety of methods including air and radiation; waste testing; drinking water, waste water and marine water methods; and others. It also provides contact information for EPA’s Regional laboratories.
	Environmental Response Team Standard Operating Procedures for Soil Sampling	EPA’s Region 6 developed this guidance to describe the procedures for the collection of representative soil samples.
	Environmental, Health, and Safety Research Strategy	The 2011 Environmental, Health, and Safety Research Strategy provides guidance for the save, effective, and responsible use of nanotechnology to Federal agencies that produce the scientific information for risk management, regulatory decision-making, product use, research planning, and public outreach. Core research areas include human exposure assessment, environment, and risk assessment and risk management methods.
	Environmentally Preferable Purchasing Program (EPP)	The EPP website provides information on finding and evaluating green products and services along with tools and other links.
	EOS – EarthData Exit	In partnership with NASA, the University of New Hampshire's WEB-based System for Terrestrial Ecosystem Research (EOS-WEBSTER) distributes a database that provides agricultural lands soil property data for counties within the contiguous United States. The database includes information on: high and low soil bulk density (g C/cm3 soil), high and low clay content (fraction), high and low soil organic carbon (g C/g soil), and soil pH.
	EPA On-Line Tools for Site Assessment Calculation	This website provides guidance on performing indoor air unit conversions (e.g., mg/L to ppbV).
	Estimated Per Capita Water Ingestion and Body Weight in the United States— An Update: Based on Data Collected by the United States Department of Agriculture	This resource provides updated water ingestion data that may be used to identify subpopulations at elevated risk of health effects from exposure to contaminated drinking water or to characterize the health risks of sensitive populations.
	Estimation Program Interface (EPI) Suite	EPI Suite is a Microsoft Windows-based collection of physical/chemical property and environmental fate estimation programs developed by EPA’s Office of Pollution Prevention Toxics (OPPT) and Syracuse Research Corporation (SRC).
	Evaluating Variability and Uncertainty in Guiding Principles for Monte Carlo Analysis	This report follows recommendations of the May 1996 workshop organized by the Risk Assessment Forum on use of Monte Carlo analysis. It discusses issues and advances the development of guiding principles concerning how to prepare or review an assessment based on use of Monte Carlo analysis. It includes guidance on evaluating uncertainty and variability that is specific to Monte Carlo assessments.
	Example Exposure Scenarios	This document presents a series of example exposure scenarios for various exposure pathways organized by route (i.e., ingestion, inhalation, or dermal) and demonstrates how data from the Exposure Factors Handbook can be applied for estimating exposures.
	Existing Information on PFOS Production, Use, Emissions and Pathways to the Environment and Cost/Benefits with Alternatives and Substitutes Exit	This document from the UN Economic Commission for Europe (UNECE) provides an overview of the global production, use, emissions, and exposure pathways for PFOS. It briefly describes the costs and benefits of potential alternatives to PFOS and current (as of 2006) legislative controls in place.
	Exploration of Perinatal Pharmacokinetic Issues	This resource presents information pertinent to absorption, distribution, metabolism, and excretion of environmental chemicals in pregnancy and infant development (including those ingested from breast milk).
	ExpoFacts database Exit	The European Exposure Factors (ExpoFacts) Sourcebook is a tool that acts as a database, a reference guide, and a document library aimed towards environmental exposure analysis and risk assessment. It contains population data from 30 European countries including information broken down, for example, by age, or socioeconomic status.
	ExpoFIRST (Exposure Factors Interactive Resource for Scenarios Tool)	ExpoFIRST is a standalone tool that draws from data in the EPA’s Exposure Factors Handbook for quick, easy, and flexible development of human exposure scenarios. The tool develops these scenarios based on the selections made by the user in terms of the route of exposure of interest, the media of interest, exposure descriptor, receptor (age groups) and other demographics.
	Exposure Analysis Modeling System (EXAMS)	The Exposure Analysis Modeling System (EXAMS) is a tool for evaluating the fate, transport, and exposure concentrations of synthetic organic chemicals leaching from disposal sites.
	Exposure and Fate Assessment Screening Tool (E-FAST)	Exposure and Fate Assessment Screening Tool (E-FAST) provides screening-level estimates of the concentrations of chemicals released to surface water and other media from consumer products.
	An Exposure Assessment of Polybrominated Diphenyl Ether	EPA's exposure assessment of polybrominated diphenyl ether (PBDE) provides a comprehensive assessment of the exposure of Americans to PBDEs. The report includes information on the production, use, lifecycle, and environmental fate of these persistent organic chemicals, as well as measured environmental levels and human exposure.
	Exposure Assessment Strategies Committee Exit	The Exposure Assessment Strategies Committee seeks to provide leadership in the field of exposure assessment and strategies for Environmental Health, Safety and Industrial Hygiene professionals. Links to professional development courses sponsored by the Committee can be found at this website.
	Exposure Factors Handbook	The Exposure Factors Handbook summarizes available statistical data on various factors used in assessing human exposure. This Handbook furnishes data on the factors needed to calculate human exposure to environmental agents via food and drinking water consumption, soil ingestion, inhalation rates, dermal factors and activity patterns. Population data for key exposure factors such as food and activities are included in the Handbook.
	Exposure Model for Soil-Organic Fate and Transport (EMSOFT)	EMSOFT is used to explore how chemicals in the soil can vaporize and become an inhalation exposure risk in humans. The model can predict concentrations of soil contaminants, rates of transfer into the atmosphere, and potential ingestion and dermal contact risks. EMSOFT can also estimate average contaminant concentrations at a given soil depth over time.
	Exposure Scenario for CTUIR Traditional Subsistence Lifeways Exit	This report presents updated exposure factors for the CTUIR exposure scenario, which reflects a traditional cultural subsistence lifestyle.
	EXPRESS (EXAMS - PRZM Exposure Simulation Shell)	EXPRESS has been created to combine the regulatory simulation model EXAMS and PRZM, their supporting databases, regulatory “scenarios” for major crops, and data input screens for chemical properties into a user-friendly “simulation shell” lending itself to consistent analytical practices and reproducible exposure and risk assessments. These models use a refined (i.e., Tier II) estimation of pesticide concentrations in surface waters used as drinking water sources and for aquatic ecosystem exposure assessments.
	The Facility Registry Service (FRS) Query Page	The FRS Query Page allows users to retrieve selected facility data from the national systems listed. Search strategies include combinations of the facility name, geographic location, facility industrial classification, affiliated organization and contact, program category, and national systems.
	Families and Living Arrangements	The U.S. Census Bureau provides data on housing unit types, the people residing in those units, and their relationship to each other. This website contains links to various reports including the 2012 report “American’s Families and Living Arrangements.”
	Feeding Infants and Toddlers Study (FITS) Exit	This study provides information on foods eaten by children at various stages of development.
	Fertility of American Women website	This website provides access to reports, tables and datasets related to fertility, maternity leave, and employment patterns for first-time mothers.
	Fertility of American Women: 2008 Population Characteristics	This Census report presents fertility rates for U.S. women in 2008 by various characteristics, including demographic, housing type, and occupation.
	Final Nanotechnology White Paper	The White Paper provides the following information: basic description of nanotechnology; environmental benefits of nanotechnology; risk assessment issues related to nanotechnology; review of science issues and research needs for nanotechnology and recommendations for addressing these issues/needs; description of EPA's framework for nanotechnology research.
	Finite Dose Skin Permeation Calculator	This calculator estimates fluxes, skin concentrations, and amounts absorbed from any size dose applied to partially or fully hydrated skin. The calculations are based on the model described in the references below. EPI Suite can be used to develop inputs for this calculator and other optional properties for this calculator.
	Fish Consumption Advisories – Technical Information	This website provides links to technical information related to fish advisories, including reports and chemical fact sheets, national guidance, and contact information for federal, state, and tribal fish advisory programs. An interactive map and search tool is also available for locating and viewing information on advisories by water body, fish species, chemical contaminants, or population affected.
	Food and Gill Exchange of Toxic Substances (FGETS)	Maintained by EPA’s EPA Center for Exposure Assessment Modeling (CEAM), FGETS is a food chain model that predicts chemical concentrations in fish whole body over time, considering the biological attributes of the fish and the physicochemical properties of the chemical.
	Food and Nutrient Intakes by Individuals in the United States, 1 Day 1989–91	This resource contains estimates of daily food and nutrient intakes based on results from the 1989-91 Continuing Survey of Food Intakes by Individuals (CSDII) conducted by USDA. The data were collected based on 1-day dietary recall and are tabulated by age, sex, race, and other demographic characteristics.
	Food and Pesticides	This webpage contains information on how EPA is ensuring food is safe from pesticides, how they are regulating pesticides in food, and provides links to more information on pesticides in food.
	Food Chain Models	This site provides links to six food chain models maintained by CEAM and EPA's National Health and Environmental Effects Research Laboratory (NHEERL). The models on the site are designed to determine exposure levels and effects of environmental contaminants on organisms that make up the food chain: Acute-to-Chronic Estimation (ACE) with Time-Concentration-Effect Models; Bioaccumulation and Aquatic System Simulator (BASS); Food and Gill Exchange of Toxic Substances (FGETS) simulation model; Spreadsheet-based Ecological Risk Assessment for the Fate of Mercury (SERAFM) modeling system; Web-based Interspecies Correlation Estimation (Web-ICE) application; and Watershed Health Assessment Tools Investigating Fisheries (WHATIF) software.
	Food Commodity Intake Database (FCID); What We Eat in America (WWEIA) Exit	EPA’s Office of Pesticide Programs developed the Food Commodity Intake Database (FCID) by converting NHANES data on the foods people reported eating to the quantities of agricultural commodities eaten, including water that was added in the preparation of foods and beverages. This resource also provides access to the What We Eat in America - Food Commodity Intake Database, 2003-2008 (WWEIA-FCID 2003-08).
	Food Contaminants Web Pages Exit	These web pages maintained by the European Union provide information about specific contaminants, general information about sampling and analysis of contaminants, and EU legislation governing potential food contaminants.
	Food Packing Forum Website Exit	The Food Packing Forum website provides links to information, research, and workshops on food packaging as a source of chemical food contaminants. Information includes chemical composition, structure, migration, and adverse human health outcomes at varying exposure levels.
	Food Safety and Inspection Service (FSIS)	The Food Safety and Inspection Service (FSIS) is the public health agency in the U.S. Department of Agriculture responsible for ensuring that the nation's commercial supply of meat, poultry, and egg products is safe, and correctly labeled and packaged. This website provides links to information about food safety, safe food handling, and foodborne illness and disease.
	Food Safety and Inspection Service: Fact Sheets: Production & Inspection	This resource is a series of fact sheets on dioxin in U.S. meat and poultry and includes information on dioxin in livestock, poultry, and eggs.
	Food Safety; Pesticide Residues in Food Exit	This website provides information on assessing pesticide residues in food and link to related publications.
	Food Surveys website	This website provides a variety of information about USDA’s food intake survey collection methods and data.
	Food website	This website includes links to information about food safety, food defense, guidance and regulations, compliance and enforcement, foodborne illness and contaminants, and other important information for a variety of audiences.
	FoodRisk.org Exit	FoodRisk.org is geared toward risk assessors addressing food safety. The website provides access to datasets, tutorials, tools, and links to numerous sources of information.
	Formaldehyde in Consumer Products	Building materials, smoking, household products, and the use of un-vented, fuel-burning appliances can be sources of formaldehyde in buildings. An important source of formaldehyde in homes may be pressed wood products made using adhesives that contain urea-formaldehyde (UF) resins. Information on formaldehyde sources may be found at this website.
	Fourth National Report on Human Exposure to Environmental Chemicals	This report provides information on NHANES biomonitoring data (i.e., in human blood and urine) in the U.S. population. The 4th report includes new data from 2003-2004 as well as data from the 2nd and 3rd reports (from 1999-2000 and 2001-2002, respectively). Data are included for phthalates, PFCs, PAHs, PCBs, dioxins, VOCs, metals, flame retardants, and multiple pesticides among other substances.
	Fourth National Report on Human Exposure to Environmental Chemicals, Updated Tables	This resource provides updated data on 66 chemicals included in the Fourth Report (2009), and new data on 34 chemicals not previously included.
	FQPA Index Reservoir Screening Tool (FIRST)	FIRST is a screening model designed to estimate the pesticide concentrations found in water for use in drinking water exposure assessments. It provides high-end values on pesticide concentrations that might be found in a small drinking water reservoir.
	Framework for Application of the Toxicity Equivalence Methodology for Polychlorinated Dioxins, Furans, and Biphenyls in Ecological Risk Assessment	This document describes the toxicity equivalence methodology for assessing ecological risks associated with exposure to mixtures of PCDDs, PCDFs, and dioxin-like PCBs, in which risks are assessed based on potency estimates of dioxin-like chemicals relative to 2,3,7,8-TCDD. The Ecological Toxicity Equivalence Factor (Eco-TEF) framework is intended to be a guidance document only.
	Framework for Cumulative Risk Assessment	The Framework for Cumulative Risk Assessment outlines the basic steps for conducting a cumulative risk assessment. Guidance is provided on general concepts of cumulative risk. The framework is not intended to serve as a step-by-step guide, but rather a resource for cumulative risk assessment and a building block toward the development of future guidance.
	Framework for Metals Risk Assessment	The Framework for Metals Risk Assessment identifies the unique properties, issues, and processes that risk assessors need to consider when evaluating metal compounds in EPA risk assessments.
	GCSOLAR Program	The GCSOLAR is a program that computes direct photolysis rates and half-lives of pollutants in the aquatic environment.
	General Principles for Performing Aggregate Exposure and Risk Assessments for Pesticides	This resource provides information on data inputs for aggregate exposure assessments, framework for expanded aggregate exposure, and questions to consider when conducting aggregate assessments.
	Geographical Mobility and Migration Data	This website contains links to statistics and datasets for people who move from one geographical location to another (i.e. state to state, country to country).
	German Environmental Specimen Bank (ESB) Exit	The human part of the ESB archives human samples of blood, blood plasma, urine, saliva, and hair. Samples are also collected from representative ecosystems in Germany.
	German Environmental Survey (GerES) Exit	GerES is a representative population study to determine the exposure of Germany's general population to environmental contaminants. Biomonitoring data have been collected since the mid-1980s.
	Global Anthropogenic Emissions of Non-CO2 Greenhouse Gases 1990–2020	The data in the appendices to the Global Anthropogenic Emissions of Non-CO2 Greenhouse Gases (1990-2020) report provide historical and projected estimates of emissions from over 90 countries and 8 regions for all major non-CO2 greenhouse gas emission sources. The gases included in this data set are methane (CH4), nitrous oxide (N2O), and the high global warming potential (high GWP) gases (hydrofluorocarbons [HFCs], perfluorocarbons [PFCs], and sulfur hexafluoride [SF6]).
	The Good Nano Guide Exit	The Good Nano Guide is an internet collaboration platform currently in beta-test version. It serves as a forum for researchers and professionals involved with nanotechnology and nanomaterials to share information on best practices for managing nanomaterials in the workplace.
	Great Lakes Environmental Database (GLENDA)	The Great Lakes Environmental Database (GLENDA) houses environmental data on a wide variety of chemicals measured in water, biota, sediment, and air in the Great Lakes area.
	Great Lakes Fish Monitoring and Surveillance Program (GLFMSP)	The Great Lakes Fish Monitoring and Surveillance Program (GLFMSP) measures the concentrations of legacy and emerging chemicals in Great Lakes whole fish tissue to track the effectiveness of toxic reduction efforts, track environmental trends, and inform programs that issue health information on chemicals of concern.
	Green Chemistry Program at EPA	This website provides information on EPA's green chemistry program charged with design of chemical products and processes that reduce or eliminate the use and generation of hazardous substances.
	Greener Products – Consumer Information	This website provides guidance on selecting greener products. Links to several related EPA initiatives and resources are provided.
	Ground Water and Drinking Water	This resource provides links to basic information on drinking water, drinking water standards and regulations, drinking water requirements for states and public water systems, drinking water analytical methods and many other drinking water topics.
	Ground Water Rule: Source Water Monitoring Guidance Manual	This document provides guidance on triggered and assessment source water monitoring issues (e.g., fecal indicators, sample collection, laboratory methods) as well as information on the Ground Water Rule requirements.
	Groundwater Models	The EPA CEAM Groundwater Models provides links to three groundwater models designed to quantify the flow, transport, and concentrations of contaminants in subsurface media: Three-Dimensional Finite Element Model of Water Flow Through Saturated-Unsaturated Media (3DFEMWATER)/Three-Dimensional Lagrangian-Eulerian Finite Element Model of Waste Transport Through Saturated-Unsaturated Media (3DLEWASTE); Pesticide Root Zone Model (PRZM3); and Wellhead Analytic Element Model (WhAEM2000).
	Guidance Document for the Implementation of United States Environmental Protection Agency Method 5035: Methodologies for Collection, Preservation, Storage, and Preparation of Soils to be Analyzed for Volatile Organic Compounds	California EPA prepared this guidance to summarize the sampling options and procedures for the collection of soil samples for VOC analysis.
	Guidance for Assessing Chemical Contaminant Data for Use in Fish Advisories - Volume 2: Risk Assessment and Fish Consumption Limits	This document provides guidance on the development of risk-based fish meal consumption limits for 25 high-priority target analytes that include organochlorine and organophosphate pesticides, PAHs, PCBs, dioxins/furans, and some metals.
	Guidance for Developing Ecological Soil Screening Levels	This document provides guidance on the process used to derive a set of risk-based ecological soil screening levels. Although the guidance is developed for ecological risk assessments, Appendix A of attachment 1-4 contains a database on background soil concentration.
	Guidance for Developing Ecological Soil Screening Levels (Eco-SSLs): Exposure Factors and Bioaccumulation Models for Derivation of Wildlife Eco-SSLs	Chapter 3 of this document provides information on estimating bioaccumulation of contaminants in plants, small mammals, and birds.
	Guidance for Dietary Intake Exposure Assessment (GUIDEA) Exit	GUIDEA is an ongoing initiative by the ILSI Europe Food Intake Methodology Task Force. It is based on the wide range of individual guidance documents already available on exposure assessment. The GUIDEA website contains key information on dietary intake and exposure.
	Guidance for Evaluating the Oral Bioavailability of Metals in Soils for Use in Human Health Risk Assessment	This resource provides guidance on how to assess site-specific oral bioavailability of metals in soils for use in human health risk assessments.
	Guidance for Identifying Populations At Risk from Mercury Exposure Exit	This document is intended to inform countries concerned about the potential health impacts of mercury pollution and, if necessary, to assist in identifying specific subpopulations that may be at risk. Approaches that have been used to estimate exposure to mercury, including biomonitoring and methods that use data on fish consumption and mercury levels in fish are described. It also describes various environmental models that can be useful in predicting exposure to mercury. The document also provides an overview of the assessment of mercury exposures for some specific exposure scenarios, including occupational and other “hot spot” exposures.
	Guidance for Industry: Preparation of Premarket Submissions for Food Contact Substances: Chemistry Recommendations	This guidance document contains FDA’s recommendations pertaining to chemistry information that should be submitted in a food contact notification or food additive petition for a food-contact substance.
	Guidance for Industry: Use of Recycled Plastics in Food Packaging: Chemistry Considerations	This report lays out chemistry issues that FDA recommends recycled plastic manufacturers consider during their evaluation of a recycling process for producing material suitable for food contact applications.
	Guidance for Obtaining Representative Laboratory Analytical Subsamples from Particulate Laboratory Samples Exit	This guidance was developed by EPA’s Office of Research and Development to advise soil samplers and laboratories about the issues involving sampling of soils and other solid particulate materials. Experiments showed that common soil collection, homogenization and subsampling techniques were ineffective. Recommendations for improved techniques are provided.
	Guidance for Reporting on the Environmental Fate and Transport of the Stressors of Concern in Problem Formulations	This document developed by EPA’s Office of Pesticides provides information on estimating chemical and physical properties of chemicals and other environmental fate properties including sorption, degradation, dissipation, and bioconcentration that are relevant to characterizing environmental fate and transport.
	Guidance for the Sampling and Analysis of Lead in Indoor Residential Dust for Use in the Integrated Exposure Uptake Biokinetic (IEUBK) Model	This document recommends "methods for collecting and analyzing indoor residential dust data to estimate the mean concentration of lead in dust for use in the IEUBK model".
	Guidance for Use of Probabilistic Analysis in Human Health Risk Assessment Exit	The purpose of this document is to present a typical set of exposure factors and equations for calculating exposures for various exposure routes applicable to human receptors. Exposure estimation equations cross-referenced to each exposure route are provided.
	Guidance Manual for the Assessment of Joint Toxic Action of Chemical Mixtures	This manual provides guidance on assessing exposure to chemical mixtures at hazardous waste sites and in determining how that exposure might impact public health due to additivity and/or interactions of a combination of chemicals.
	Guidance Manual For The Testing of Manufactured Nanomaterials: OECD's Sponsorship Programme Exit	Developed by the Organization for Economic Cooperation and Development, this guidance manual describes the testing program for manufactured nanomaterials, including selection of the test materials and test designs.
	Guidance on Assessment Factors to Derive a Derived No-Effect Levels (DNEL) Exit	This European guidance document provides a review of assessment factors (AF) used in Derived No-Effect Levels (DNEL), which are used by chemical manufacturers and importers to justify chemical safety assessments (CSA), as required by REACH. The review examined the validity of AF used in R.8 Guidance and predicts the increased difficulty of balancing DNEL with exposure predictions if the use of default AF continues.
	Guidance on Choosing a Sampling Design for Environmental Data Collection for Use in Developing a Quality Assurance Project Plan	This guidance document provides information on how to develop sampling designs to collect environmental measurement data.
	Guidance on Cumulative Risk Assessment of Pesticide Chemicals That Have a Common Mechanism of Toxicity	This guidance document provides information on evaluating and estimating potential human risks associated with multichemical and multipathway exposures to pesticides that act by a common mechanism of toxicity.
	Guidance on Cumulative Risk Assessment, Part 1: Planning and Scoping	This document precedes EPA’s Framework for Cumulative Risk Assessment and provides information on the planning and scoping stage of cumulative risk assessments. This resource also documents EPA’s movement beyond traditional single-stressor, single-pathway assessments.
	Guidance on Incremental Sampling for Soils Exit	This is a web-based document developed by the Incremental Sampling Methodology (ISM) Team of the Interstate Technology and Regulatory Council (ITRC). It provides detailed information about what incremental soil sampling is, the benefits of using it for contaminated site investigation and risk characterization, and the techniques for applying it both in the field and in the laboratory.
	Guidance on Information Requirements and Chemical Safety Assessment; Chapter R.14: Occupational Exposure Estimation Exit	This guidance provides tools and parameters to support occupational exposure assessment and exposure scenario building under REACH.
	Guidance on Selecting Age Groups for Monitoring and Assessing Childhood Exposures To Environmental Contaminants	This document provides guidance to EPA scientists on selecting age groups to consider when assessing childhood exposure and potential dose to environmental contaminants.
	Guidance on the Use of Probabilistic Methodology for Modeling Dietary Exposure to Pesticide Residues Exit	This document provides guidance on performing basic probabilistic assessments for dietary exposure to single and multiple active substances. Topics covered include problem formulation, probabilistic methods for quantifying some of the major sources of variability and uncertainty affecting dietary exposure to pesticides, characterizing the upper tail of the exposure distribution, and approaches to validating probabilistic assessment approaches. A checklist of key issues to consider when preparing a report on probabilistic exposure assessment and several case studies is also included.
	Guide to Considering Children's Health When Developing EPA Actions: Implementing Executive Order 13045 and EPA's Policy on Evaluating Health Risks to Children	This document is a step-by-step guide to assist EPA in integrating children’s health considerations into their Action Development Process (ADP).
	Guide to State and Local Census Geography website	This U.S. Census Bureau website provides geological information from the 2010 census for each individual state including but not limited to land area, population density, bordering states postal abbreviation, FIPS/ANSI code, history, American Indian areas, local boundaries and other districts.
	Guidelines for Assessing Human Health Risks from Environmental Hazards Exit	This Australian guidance document provides a methodology and checklist designed for environmental health risk assessment of chemical health hazards with the goal of streamlining environmental health risks assessments to increase precision and timeliness of reports and increase transparency of the decision-making process. Although the methodology was designed for chemical health hazards, it can be applied to a broad range of environmental health risk assessments including physical, microbiological, and mixtures of environmental health hazards.
	Guidelines for Carcinogen Risk Assessment	These guidelines revise and replace EPA’s 1986 Guidelines for Carcinogen Risk Assessment. They provide guidance for developing and using risk assessments and basic information about EPA’s risk assessment methods.
	Guidelines for Ecological Risk Assessment	This report describes general principles and gives examples to show how ecological risk assessment can be applied to a wide range of systems, stressors, and biological, spatial, and temporal scales.
	Guidelines for Exposure Assessment	The Guidelines for Exposure Assessment is the “go to” resource for planning and conducting human exposure assessments. Guidance is also provided on general concepts of exposure, including definitions, uncertainty, suggestions for presenting results, and tools used for conducing exposure assessments. Information relevant to wildlife exposure to chemicals and human exposure to biological, radiological, and noise agents is also discussed in this resource.
	Guidelines for Exposure Assessment: Table 2. Examples of Types of Measurements to Characterize Exposure-Related Media and Parameters	This table illustrates some of the types of measurements used by exposure assessors, along with notes describing additional information often needed to use these measurements in estimating exposure or dose.
	Guidelines for the Health Risk Assessment of Chemical Mixtures	The 1986 guidelines describe procedures on evaluating and estimating potential human risks associated with exposures to chemical mixtures consisting of two or more chemicals.
	Guidelines for the Identification and Management of Lead Exposure in Pregnant and Lactating Women	This resource provides information on preventing lead exposure during pregnancy, assessment and blood lead testing during pregnancy, medical and environmental management to reduce fetal exposure, breastfeeding, and follow up of infants and children exposed to lead in utero.
	Guidelines for the Study of Dietary Intakes of Chemical Contaminants Exit	WHO guidelines provide information about ingestion exposure methods, including duplicate portion studies; analysis of chemical contaminants in food; and calculation and extrapolation of results.
	Guiding Principles for Monte Carlo Analysis	Guiding Principles for Monte Carlo Analysis provides a minimum set of principles to ensure good scientific practices when developing a probabilistic assessment with a focus on Monte Carlo analysis. This resource also includes guidance for assessors on selecting input data and distributions for probabilistic assessments.
	Handbook for Use of Data from the National Health and Nutrition Examination Surveys (NHANES): A Goldmine of Data for Environmental Health Analyses	The NHANES dataset contains a tremendous amount of human health, nutrition, and exposure information. This handbook was designed to make the NHANES database more accessible to EPA staff. Topics covered by this resource include: detailed information on NHANES content; how to obtain NHANES data; types of analyses that can be conducted with NHANES data; and use of NHANES stored biological specimens. Analysis issues (i.e., weighting and non-response) and limitations of NHANES data are also covered in this resource.
	Handbook of Radiochemical Analytical Methods	This report describes the method developed for the determination of strontium-89 and strontium-90 in food, vegetation, and tissue samples.
	Handbook of Suggested Practices for the Design and Installation of Ground-Water Monitoring Wells	The Handbook of Suggested Practices for the Design and Installation of Ground-Water Monitoring Wells has been prepared as an aid to owners and operators of facilities as well as others with the design, construction, and installation of ground water monitoring wells.
	Harmonized Test Guidelines: Series 875, Occupational and Residential Exposure Test Guidelines	The Final guidelines in this Series have been developed by the Office of Chemical Safety and Pollution Prevention (OCSPP) for use in the testing of pesticides and toxic substances to develop data for submission to the Agency. The guidelines in Series 875 cover test methods for exposure to pesticides during and following application. Guidelines 875.1100, 875.1200, and 875.2400 specify guidelines for testing dermal exposures, including exposures to contaminants in soil via this pathway. Guidelines 875.1300, 875.1400, and 875.2500 specify guidelines for testing inhalation exposures (indoor and outdoor).
	Hazardous Air Pollutant Exposure Model (HAPEM)	HAPEM is a screening-level exposure model designed to assess average long-term inhalation exposures of the general population or a specific sub-population to various air toxics over spatial scales ranging from urban (large city) to national; activity patterns and multiple microenvironments can be considered.
	Hazardous Substances Data Bank (HSDB)	The Hazardous Substances Data Bank (HSDB) is maintained by the National Library of Medicine and provides comprehensive, peer-reviewed toxicology data for about 5,000 chemicals, including information on synonyms and formulations, manufacturing and use, analytical methods, environmental fate and exposure, physical-chemical properties, and occupational standards. It also includes summary information on sources and concentrations of chemicals in the environment.
	Health & Education: Dioxins	This website contains a series of pages and PDFs regarding NIEHS actions on dioxins and general information about dioxin human health effects.
	Health and Safety Estimation and Assessment of Substance Exposure (EASE)	This resource examines the underlying structure and philosophy of the Estimation and Assessment of Substance Exposure (EASE) model version 2.0, developed by the UK Health and Safety Executive (HSE). EASE is a knowledge-based modal used by regulators for assessing new and existing substances. Information was documented by gathering surviving evidence and interviewing personnel involved in its creation and development. Twenty seven stakeholders participated in structured interviews on issues such as the limitations of the model, suggestions for improvement and accuracy and precision. They were also asked to comment on what outputs they would like to obtain from an ideal model. Recommendations for the structure of a revised exposure model are also provided.
	Health Effects Assessment Summary Tables (HEAST)	HEAST was developed by EPA for the Superfund and Resource Conservation and Recovery Act (RCRA) hazardous waste programs and includes human health risk and toxicity reference values for key contaminants at hazardous waste sites.
	Health Effects of Exposures to Mercury	This website provides information related to the health effects of elemental mercury, methylmercury, and other mercury compounds.
	The Health Risk Assessment Guidance for Metals Exit	This fact sheet documents and analyzes various approaches to choosing assessment factors in health risk assessments for metals with the objective of catalyzing consistent approaches in future European Union risk assessments. The fact sheet focuses on the methodology for choosing the appropriate assessment factors for the criteria used and the derivation of reference values for health endpoints. The fact sheet considers toxicology endpoints and deficiency level margins, the natural background of metal levels, input from the metal industry on margin of safety (MOS) values, and previous EU risk assessments in its analysis.
	Health Risk Assessment Guidance for Metals. Assessment of Occupational Dermal Exposure and Dermal Absorption for Metals and Inorganic Metal Compounds. Fact Sheet 01 Exit	This fact sheet provides guidance on how to assess occupational dermal exposure and how to measure and evaluate dermal absorption specifically for metals and their inorganic compounds. Organometallic compounds are not covered by this resource as they behave much differently than inorganic metal compounds.
	High Performance Products Database Exit	CHPS developed the high performance products database in partnership with U.S. EPA and California's Department of Resources Recycling and Recovery (CalRecycle). This searchable database is designed to help schools identify available products to meet CHPS and other green building criteria. The database identifies low-emitting materials and other attributes including recycled content, rapidly renewable material content, organically grown material content, Forest Stewardship Council (FSC) Certified wood products, and life cycle and multiple attribute claims.
	High Production Volume Information System (HPVIS)	HPVIS is a database that provides health and environmental effects information regarding chemicals produced or imported into the United States. The HPVIS allows users to search for chemical summaries, test plans, and new data organized into four disciplines: physical/chemical properties, environmental fate and pathways, ecotoxicity, and mammalian.
	High School Athletics Participation Data Exit	The National Federation of State High School Associations provides yearly statistics on the number of high school males and females participating in various sports including field sports (football, track and field, baseball, soccer, golf) and pool sports (swimming and diving).
	High-throughput exposure forecasting	This factsheet highlights several high-throughput exposure models.
	Household Products Database (HPD)	The HPD database contains information on products, manufacturers, chemical ingredients, safety and handling, and potential health effects for various product categories, including auto, inside the home, landscape/yard, home maintenance, pet care, arts/crafts, personal care products, home office, and pesticides.
	Housing Topics website	The U.S. Census Bureau collects housing data from several surveys such as the American Community Survey (ACS), American Housing Survey (AHS), Current Population Survey (CPS), and the Housing Vacancies and Homeownership Survey (HVS). Financial data relating to home and/or rental properties such as rents, mortgages, and utilities paid, along with statistics for vacancy, ownership, physical residential building characteristics and other data are available on this site.
	HPA Contaminated Land Information Sheet: Risk Assessment Approaches for Polycyclic Aromatic Hydrocarbons (PAHs)	This document discusses the use of Toxic Equivalency Factor versus surrogate marker approach to conducting PAH cumulative risk assessment.
	Human and Environmental Risk Assessment (HERA) on Ingredients of Household Cleaning Products: Guidance Document Methodology Exit	This document provides guidance for European Union (EU) human health and environmental risk assessment. In particular, the HERA project pertains to exposure following household use or disposal to the environment from ingredients in household cleaning products. The document contains guidance on human health risk assessment including consumer contact scenarios and exposure routes, the latest technical guidance documents on EU risk assessments, linkages with the developing REACH process, and an amendment for cosmetic ingredients. This version supersedes the April 2002 edition.
	Human Biomonitoring Commission (HBC) Exit	HBC was established in 1992 as a joint effort between Germanys’ Federal Health Office and Federal Environment Agency. The Commission, composed of experts who are appointed every three years, seeks to clarify fundamental and practical issues related to human biomonitoring (HBM). Their efforts have included derivation of reference values (e.g., bisphenol A in urine; PCBs in human milk) and HBM values (e.g., cadmium, mercury, bisphenol A, PCB); monographs on individual substances; and position papers on various contaminants and analytical approaches (e.g., formaldehyde, PCBs in indoor air, creatinine correction approach, hair analyses).
	Human Biomonitoring for Environmental Chemicals Exit	This resource authored by the Committee on Human Biomonitoring for Environmental Toxicants and the National Research Council provides a framework for improving the use of biomonitoring data including developing and using biomarkers (measures of exposure), research to improve the interpretation of data, ways to communicate findings to the public, and a review of ethical issues. A summary of biomonitoring efforts in the United States and internationally is also provided.
	Human Exposure Assessment (Environmental Health Criteria 214): Assessing Exposure through Food Exit	This document published by IPCS describes concepts in human exposure assessment; Sections 7.4 and 7.4.1 provide details on direct measurements of exposures through food.
	Human Exposure Assessment (Environmental Health Criteria 214): Direct Approaches to Exposure Assessment Exit	This document published by IPCS describes concepts in human exposure assessment; section 3.5.1 and chapter 7 provide details on direct measurements of exposure. Tables 7-21 through 7-24 list types of monitors made by a variety of manufacturers that are capable of measuring personal inhalation exposure.
	Human Exposure Model (HEM)	HEM is used in performing risk assessments for major point sources of air toxics specifically for the inhalation exposure pathway. HEM provides ambient air concentrations for use with unit risk estimates and inhalation reference concentrations to estimate cancer risk and noncancer hazard, respectively, for the air toxics modeled.
	Human Health Benchmarks for Pesticides	This EPA website provides a table of human health benchmarks for acute (one-day) and chronic (lifetime) exposures for 363 pesticides that may be found in surface or ground water sources of drinking water.
	Human Health Criteria - Methylmercury	This website provides information on the human health criterion for methylmercury in fish, including fact sheets and guidance documents.
	Human Health Risk Assessment Protocol (HHRAP) for Hazardous Waste Combustion Facilities	HHRAP describes the evaluation of multi-pathway, site-specific human health risk assessments and was developed specifically for assessment of hazardous waste combustors; it is applicable to other exposure scenarios as well.
	Human Health Risk Assessment Toolkit: Chemical Hazards Exit	This resource was developed to help professionals and other decision makers assess the magnitude of potential risks to human health associated with exposure to the chemicals. The Toolkit provides road maps for conducting chemical risk assessments; identifies information that must be gathered to complete an assessment; and provides a resource list for obtaining information and methods necessary for conducting a risk assessment.
	Human Health Risk Assessment website	This website contains basic information on how a human health risk assessment is conducted, with information on the planning and scoping process, hazard identification, dose-response assessment, exposure assessment, and risk characterization.
	Hydrocarbon Spill Screening Model (HSSM)	This model developed by EPA can be used to model subsurface releases of fuel hydrocarbons (e.g., leaking underground storage tanks).
	Hydrodynamic, Sediment, and Contaminant Transport Model (HSCTM2D)	The HSCTM2D program is a finite element modeling system for simulating two-dimensional, vertically-integrated, surface water flow (typically riverine or estuarine hydrodynamics), sediment transport, and contaminant transport.
	Identification of Time-integrated Sampling and Measurement Techniques to Support Human Exposure Studies	This resource presents a literature review on the identification and evaluation of methods used to classify exposure.
	IH SkinPerm Exit	This website for the Exposure Assessment Strategies Committee provides links to tools for the practicing Industrial Hygienist including IH SkinPerm tool, which was developed to help increase understanding of dermal absorption and provide a practical tool to estimate dose from dermal exposure, factoring in evaporation and absorption.
	IHEST Exit	This website for the Exposure Assessment Strategies Committee provides links to tools for the practicing Industrial Hygienist including the IH Exposure Scenario Tool (IHEST) which guides the assessor through the process of collecting general information about the workplace, specific scenario and agents(s), and estimating exposure.
	IHSTAT Excel tool Exit	This website for the Exposure Assessment Strategies Committee provides links to tools for the practicing Industrial Hygienist including IHStat which can be used to calculate a variety of exposure statistics, perform goodness of fit tests, and graph exposure data.
	The Impact of Home and Community Gardening in America Exit	The National Gardening Association, funded by Scotts Miracle-Gro Company, conducted a survey to obtain information pertaining to gardening activities (including attitudes toward childhood gardening).
	Incorporating Human Interindividual Biotransformation Variance in Health Risk Assessment	This article describes the extent to which human interindividual enzyme variance can influence parameters in PBPK models (i.e., the detoxication of a toxic chemical through metabolism) that may influence risk.
	The Incorporation of Water Treatment Effects on Pesticide Removal and Transformations in Food Quality Protection Act (FQPA) Drinking Water Assessments	This EPA/OPP report describes pesticide removal and transformation in treated drinking water and how OPP considers impacts of drinking water treatment in FQPA drinking water exposure assessments.
	Indexes to Part 180 Tolerance Information for Pesticide Chemicals in Food and Feed Commodities	This Web page describes information that may be helpful in finding specific pesticide tolerance information available in the Code of Federal Regulations (CFR) at Part 180. It is intended to help registrants, scientists, importers, trade associations, extension agents identify tolerances (maximum residue levels) or exemptions from tolerance requirements for a food or feed commodity, pesticide chemicals that belong to a particular commodity, crop group, or crop subgroup, and pesticide chemicals that belong to a particular pesticide type or pesticide family.
	Indoor Air Quality (IAQ)	This resource provides links to fact sheets, reports, and other sources of information related to indoor air quality.
	Indoor Air Quality Building Education and Assessment Model (I-BEAM)	I-BEAM is a guidance tool designed for use by building professionals and others interested in indoor air quality in commercial buildings. I-BEAM supplements EPA's Building Air Quality guidance and was designed to provide information about managing IAQ in commercial buildings. I-BEAM contains text, animation/visual, and interactive/calculation components that can be used to perform a number of diverse tasks.
	Indoor Air Unit Conversion	This website provides units conversion assistance for air concentrations. Air concentrations expressed in units of mass-per-mass (e.g., ppm or ppb) may be converted to units of mass-per-volume (e.g., mg/m3 or ug/m3) using the ideal gas law, and information about the molecular weight of the compound, air temperature and pressure.
	Industrial Hygiene Model (IH Mod) Exit	This website for the Exposure Assessment Strategies Committee provides links to tools for the practicing Industrial Hygienist including IH-Mod which is an Excel spreadsheet containing several algorithms used for calculating airborne concentrations of chemicals. Algorithms are provided for 12 models including well-mixed room, eddy diffusion, two-zone, field plume, and estimating contamination from small spills.
	Industrial Source Complex Model (ISC3)	ISC3 is a steady-state Gaussian plume model which can be used to assess pollutant concentrations from a wide variety of sources associated with an industrial complex.
	Industrial Waste Air Model (IWAIR)	IWAIR is used to evaluate inhalation risks for workers and residents in the vicinity of waste management units. It includes models to estimate emissions, dispersion, and risk.
	Industrial Waste Management Evaluation Model (IWEM)	IWEM is designed to assist users in performing Tier 1 and Tier 2 analyses to determine the most appropriate waste management unit design to minimize or avoid adverse ground water impacts, by evaluating types of liners, hydrogeologic conditions of the site, and toxicity and expected leachate concentrations of the anticipated waste constituents.
	Industry Profile for an OSHA Standard	This webpage from OSHA allows users to determine which Standard Industrial Classification (SIC) groupings have the most violations of a specified Federal or State OSHA standard.
	Infant Feeding Practices Study II	The Infant Feeding Practices Study II is a longitudinal consumer-based study that is jointly sponsored by the Center for Disease Control, Food and Drug Administration, and several other federal agencies to evaluate infant feeding practices, mothers’ diets during pregnancy and post-partum and other factors. Raw data are available.
	Information, Regulations and Guidance about Lead in Consumer Products	This webpage provides links to documents regarding lead in consumer products including regulatory summaries, testing laboratories & methods, and specific product information.
	The Inside Story: A Guide to Indoor Air Quality	This resource provides information on indoor air quality concerns, sources of indoor air pollution, tips for improving air quality, and provides a reference guide for major indoor air pollutants in the home.
	Integrated Exposure Uptake Biokinetic (IEUBK) Model for Lead in Children	The IEUBK Model is designed to model exposure from lead in air, water, soil, dust, diet, and paint and other sources with pharmacokinetic modeling to predict blood lead levels in children 6 months to 7 years old. Links to the model and supporting documentation are provided at this website. (EPA’s Adult Lead Model is used to predict blood lead levels in adults.)
	Integrated Risk Information System (IRIS)	The IRIS database contains information on more than 550 chemical substances and the human health effects that might result from exposure to these substances.
	Interactive Chemical Safety for Sustainability (iCSS) Dashboard	The iCSS ToxCast Dashboard provides an interactive tool to explore rapid, automated (or in vitro high-throughput) chemical screening data generated by the Toxicity Forecaster (ToxCast) project and the federal Toxicity Testing in the 21st century (Tox21) collaboration. The iCSS ToxCast Dashboard integrates data from various sources, including ExpoCast, DSSTox, PhysChemDB, and CPCat.
	Intermedia Transfer Factors for Contaminants Found at Hazardous Waste Sites: TCDD	This document was prepared to support the transport and transformation modules within the CalTox model for 2,3,7,8-Tetrachlorodibenzo-p-Dioxin (TCDD).
	International Programme on Chemical Safety (IPCS) Principles and Methods for Risk Assessment of Chemicals in Food Exit	The WHO's International Programme on Chemical Safety's guidelines describe the assessment of chemicals in food, including chemical analysis, toxicological assessment, and risk assessment.
	Internet Geographical Exposure Modeling System (IGEMS)	IGEMS incorporates models and data for ambient air, surface water, soil, and ground water in one system. Each model produces results files that can be saved and used with statistical software applications or other database programs. IGEMS can create graphics and Geographical Information System (GIS) files for displaying environmental modeling results.
	An Introduction to Indoor Air Quality (IAQ): Volatile Organic Compounds (VOCs)	This website provides introductory-level information VOCs, including sources, health effects, levels in homes, steps to reduce exposure, and standards/guidelines.
	Issue Paper on the Bioavailability and Bioaccumulation of Metals	This paper discusses principles of bioavailability and bioaccumulation with respect to metals.
	Issue Paper on the Human Health Effects of Metals	This paper discusses issues important to consider in developing a framework for performing human health assessments for exposure to metals and metal compounds. Topics covered include measures of exposure to metals, interactions between metals, human health risks.
	Issue Paper on Metal Exposure Assessment	This paper presents the results of a working group to develop a consistent means of assessing hazards and risks of metals. Exposure to aquatic, terrestrial and human health receptors are addressed including considerations for background exposure, methods to estimate exposure, and potential pathways for metal exposure.
	Japanese Exposure Factors Handbook Exit	The Japanese Exposure Factors Handbook includes exposure factors for various lifestyle activities (e.g., showering, time spent outdoors), food consumption rates or different food products (e.g., vegetables, shellfish), physical attributes (e.g., body weight, breathing rate), and other environmental conditions (e.g., floor space of house, mode of commute).
	Johnson and Ettinger Model for Subsurface Vapor Intrusion into Buildings	This resource includes a series of models used to evaluate vapor intrusion into buildings. Several modifications have been made to the original models including the ability to edit data for existing chemicals, add new chemicals, and default values recommended in Appendix G of the EPA OSWER Draft Guidance for Evaluating the Vapor Intrusion to Indoor Air Pathway have been incorporated into the models.
	Joint Institute for Food Safety and Applied Nutrition (JIFSAN) Exit	The Joint Institute for Food Safety and Applied Nutrition (JIFSAN) is a partnership between the United States Food and Drug Administration (FDA) and the University of Maryland to ensure the safety of the food supply. JIFSAN houses EPA’s Food Commodity Intake Database.
	JRC NANOhub Exit	Launched in 2009, this database is a comprehensive IT platform with the goal of managing information on nanomaterials relevant for safety and risk assessment. Additionally, it hosts other collections of research project data.
	A laboratory method to determine the retention of liquids on the surface of hands. Report to USEPA/OPPT, Contract 68-02-4254	This USEPA/OPPT report presents data from three laboratory trials designed to estimate the amount of liquid retained on the surface of the skin. This information is useful for characterizing dermal exposure using the film thickness methodology.
	Landfill Gas Emissions Model (LandGEM)	LandGem is an automated estimation tool with a Microsoft Excel interface to estimate emission rates for total landfill gas, methane, carbon dioxide, non-methane organic compounds, and individual air pollutants from municipal solid waste landfills.
	Lead at Superfund Sites: Software and Users' Manuals	EPA’s Integrated Exposure Uptake Biokinetic Model for Lead in Children is used to predict blood lead levels for children aged 6 months to 7 years. The ALM Model is designed to model exposure from lead in air, water, soil, dust, diet, and paint and other sources with pharmacokinetic modeling to predict blood lead levels adults. This page provides links for downloading these lead models and supporting documentation, including technical reports, guidance documents, FAQs, short sheets related to use of the IEUBK model and the ALM, and other links with additional information related to lead and lead cleanup.
	Lead in Drinking Water	This website provides basic information about lead as a drinking water contaminant, its standards in drinking water, and links to numerous publications.
	Lead Screening During Pregnancy and Lactation Exit	This document presents the opinion of the Committee on Obstetric Practice regarding screening for lead exposure during pregnancy and lactation.
	Lead website	This EPA website provides links to lead information, including sources of exposure, health effects, and laws and regulations, with links specific to lead poisoning and protecting pregnant women, nursing mothers, and children.
	Lessons Learned on Planning and Scoping for Environmental Risk Assessments	This handbook is aimed at helping agency scientists and managers as well as interested parties adopt formal planning and scoping practices to improve environmental risk assessments. It provides lessons learned from case studies following the release of the 1997 “Guidance on Cumulative Risk Assessment – Part 1. Planning and Scoping.”
	LifeLine Customized Dietary Assessment Software™ Exit	LifeLine Customized Dietary Assessment Software™ allows users to calculate dietary exposure and risks from unique diets.
	LifeLine™ Model Exit	LifeLine™ was designed to characterize population-based aggregate and cumulative exposures and risks from pesticide residues in food and tap water as well as in the home following residential uses.
	Lifestage versus Subpopulation	This website provides guidance on EPA’s use of the terms lifestage and subpopulation and also recommended age groups for childhood.
	Local Drinking Water Information	This U.S. EPA website provides links to local water quality reports (Consumer Confidence Reports [CCRs]) for states and territories and the Safe Drinking Water Hotline.
	Long-Chain Perfluorinated Chemicals (PFCs) Action Plan	Long-Chain Perfluorinated Chemicals (PFCs) Action Plan is based on EPA’s initial review of readily available use, exposure, and hazard information on PFCs. The document provides hazard, fate, and exposure characterization summaries and describes risk management considerations.
	Marriage and Divorce website	While the U.S. Census Bureau is not the official source for marriage and divorce data, they provide links to data and special reports presenting marriage and divorce statistics in the United States.
	MCRA: Monte Carlo Risk Assessment Exit	MCRA quantifies dietary exposure to chemicals as a distribution by combining data on food consumption with data on concentrations of chemicals in foods.
	Memorandum for the Heads of Executive Departments and Agencies: Policy Principles for the U.S. Decision-Making Concerning Regulation and Oversight of Applications of Nanotechnology and Nanomaterials	This memo from John Holdren, Assistant to the President for Science and Technology, discusses policy principles for the U.S. decision-making concerning regulation and oversight of applications of nanotechnology and nanomaterials.
	Mercury Concentrations in Fish: FDA Monitoring Program	This resource provides mercury and methyl mercury concentration levels in certain species of fish and shellfish for various years from 1990–2010.
	Mercury in Consumer Products	This website provides information on consumer products containing mercury and options for handling, storing, recycling, and disposing of these consumer products.
	Mercury in Consumer Products	This webpage provides information related to mercury in consumer and commercial products, including antiques, batteries, dental amalgams, CFLs and other fluorescent light bulbs, necklaces and other jewelry, paint, skin-lightening creams, switches and relays, thermometers, thermostats, and thimerosal in vaccines. Also provided is information related to reducing the use of mercury-containing products, recycling or disposing of mercury-containing products, and use of non-mercury alternatives.
	Mercury Study Report to Congress	This 8-volume report represents a 1997 state-of-the-science snapshot for mercury. The report discusses mercury emissions and deposition in the U.S., environmental fate and transport of and potential exposures to mercury, public health and environmental impacts associated with mercury emissions, and mercury control technologies. Volume VI of the Mercury Study Report to Congress is An Ecological Assessment for Anthropogenic Mercury Emissions in the United States. Volume VII of the report is Characterization of Human Health and Wildlife Risks from Mercury Exposure in the United States.
	Mercury website	This website provides links to mercury information, including sources of emissions, levels of emissions, human exposure, health effects, environmental effects, laws and regulations, and protecting yourself from exposure through releases/spills, fish consumption, and consumer products.
	Mercury: Environmental Effects	This website provides information related to the fate and transport and ecological effects of mercury.
	Mercury: Human Exposure	This website provides information related to human exposure (including fate and transport through the environment and up the food chain) to elemental mercury, methylmercury, and other mercury compounds.
	Metabolically-Derived Human Ventilation Rates: A Revised Approach Based upon Oxygen Consumption Rates	This EPA report is a companion book to the EPA Exposure Factors Handbook. It provides a revised approach for calculating individual ventilation rates directly from oxygen consumption rate. This revised approach replaces previous approaches that relied on a ventilatory equivalent based on a person’s fitness level.
	Metal Finishing Facility Risk Screening Tool (MFFRST)	This screening tool allows evaluation of the potential inhalation exposures and health risks to workers and nearby residents from air emissions from metal finishing facilities.
	Metals Environmental Risk Assessment Guidance Exit	This European guidance document provides scientific and regulatory guidance for conducting inorganic metals environmental risk assessment. The guidance includes methodologies that consider metal-specific attributes such as bioavailability, mobility and toxicity as well as spatial and temporal variations that affect those attributes. The methodologies also consider environmental and human health impacts from metals. The guidance document aims to facilitate the creation metal-specific risk assessment tools and datasets that aid regulators in making informed, science-based decisions.
	Methane: Information Related to Climate Change	This webpage provides a discussion of methane as a contributor to climate change and the Global Methane Initiative. Information on methane includes: methane characteristics/properties and its significance as a greenhouse gas; sources and emissions; projections of methane emissions and mitigation costs associated with reducing those emissions; and EPA's voluntary programs to address methane emissions reduction.
	Methodology for Assessing Health Risks Associated with Multiple Pathways of Exposure to Combustor Emissions	This guidance provides methodology on conducting indirect risk assessments for multiple pathways of exposure to combustor emissions.
	Methodology for Characterization of Uncertainty in Exposure Assessments	This resource provides a review of the statistical methods for characterizing uncertainty in exposure assessments.
	Methodology for Deriving Ambient Water Quality Criteria for the Protection of Human Health	This document addresses the development of Ambient Water Quality Criteria (AWQC) to protect human health and defines the default factors EPA uses to evaluate and ensure consistency of State water quality standards with the requirements of the Clean Water Act (CWA).
	Methods Approved to Analyze Drinking Water Samples to Ensure Compliance with Regulations	EPA has compiled a set of manuals and guidelines on analytical methods and laboratory certification for the proper monitoring of drinking water in compliance with standards.
	Methods for Assessing Consumer Exposure to Chemical Substances	Volume 7 of the 14-volume series of document on Methods for Assessing Exposure to Chemical Substances provides information related to consumer products use.
	Methods for Collection, Storage and Manipulation of Sediments for Chemical and Toxicological Analyses	This report provides guidance for collecting, handling, and manipulating sediment samples.
	Methods for Derivation of Inhalation Reference Concentrations and Application of Inhalation Dosimetry	This document describes EPA’s methodology for estimation of inhalation reference concentrations (RfCs) as benchmark estimates of the quantitative dose-response assessment of chronic noncancer toxicity for individual inhaled chemicals. It also includes discussions of general principles of dose-response assessment for noncancer assessment process, criteria to select key studies for RfC derivation, and uncertainty and data gaps using this methodology.
	Microbial Risk Assessment (MRA) Guideline	This document developed jointly by U.S. EPA and USDA Food Safety and Inspection Service provides a framework for conducting risk assessments of pathogens in food and water. The document provides a flexible set of approaches, methods, and tools for use in microbial risk assessment.
	Microbiology Laboratory Antimicrobial Testing Methods & Procedures (ATMP)	Antimicrobial testing methods & procedures (ATMP) help determine the efficacy of liquid, spray, and towelette formulations of hard surface disinfectants against infectious microorganisms. There are currently 19 methods and 30 Standard Operating Procedures (SOPs) for testing, quality control, and equipment calibration described.
	Mobile Source Air Toxics - Overview	This document presents information on mobile source air toxics and strategies for reducing risk to the public from these pollutants.
	Mobile Source Observation Database (MSOD)	The MSOD contains emission test data from in-use mobile air pollution sources such as cars, trucks, and engines from trucks and nonroad vehicles. Data are available from 1982 to present and are intended to be representative of in-use vehicle emissions in the United States. A reference guide is available for this database.
	Model Assist Exit	ModelAssist is a quantitative risk analysis reference tool that provides information on various theoretical and practical approaches used in risk analysis. It includes example models (built with @RISK®/Excel®), videos, and flow diagrams and discusses Monte Carlo simulations in addition to other topics.
	Models and Documentation of Methods for Fate, Exposure, and Risk Analysis (FERA) Models and Documentation	This site describes multimedia fate and transport models (Total Risk Integrated Methodology [TRIM] - TRIM.FaTE); human exposure models (Air Pollutants Exposure Model [APEX/TRIM.Expo Inhalation], Hazardous Air Pollutant Exposure Model [HAPEM]); risk models (TRIM.Risk, Human Exposure Model [HEM]); as well as available documentation of methods for Fate, Exposure, and Risk Analysis as compiled by the Office of Air.
	Models for Pesticide Risk Assessment: Aquatic Models	EPA's Models for Pesticide Risk Assessment webpage provides links to aquatic, terrestrial, and atmospheric exposure models as well as health effects models used to assess the risk of a pesticide to human health or the environment. This website provides links to aquatic models for estimating pesticide concentrations in food, water, non-target organisms, and residential and occupational environments. Models include PWC (Pesticide in Water Calculator), Surface Water Concentration Calculator (SWCC), PRZM-GW (Pesticide Root Zone Model for GroundWater), Pesticides in Flooded Applications Model (PFAM), FIRST (FQPA Index Reservoir Screening Tool), KABAM (Kow (based) Aquatic BioAccumulation Model), EXPRESS (EXAMS - PRZM Exposure Simulation Shell), SCIGROW (Screening Concentration In GROund Water), and Tier I Rice Model.
	Models for Pesticide Risk Assessment: Atmospheric Models	EPA's Models for Pesticide Risk Assessment webpage provides links to aquatic, terrestrial, and atmospheric exposure models as well as health effects models used to assess the risk of a pesticide to human health or the environment. This website provides links to atmospheric models used to predict the deposition patterns of pesticides released into the atmosphere. Models include AGDISP (AGricultural DISPersal), AgDRIFT (modified version of AGDISP), PERFUM (Probabilistic Exposure and Risk Model for FUMigants), SOFEA (SOil Fumigant Exposure Assessment), and FEMS (Fumigant Exposure Modeling System).
	Models for Pesticide Risk Assessment: Health Effects Models	EPA's Models for Pesticide Risk Assessment webpage provides links to aquatic, terrestrial, and atmospheric exposure models as well as health effects models used to assess the risk of a pesticide to human health or the environment. This website provides links to health effects models for predicting effects to humans from exposure to pesticides. Models include DEEM (Dietary Exposure Evaluation Model)/CALENDEXTM - FCID, CARES (Cumulative and Aggregate Risk Evaluation System), Indirect Dietary Residential Exposure Assessment Model (IDREAM), LifeLine, OPHED (Occupational Pesticide Handler Exposure Data), OPPED (Occupational Pesticide Post-application Exposure Data), REx (Residential Exposure Assessment), SHEDS (Stochastic Human Exposure and Dose Simulation Model), and SWIMODEL (Swimmer Exposure Assessment Model).
	Models for Pesticide Risk Assessment: Terrestrial Models	EPA's Models for Pesticide Risk Assessment webpage provides links to aquatic, terrestrial, and atmospheric exposure models as well as health effects models used to assess the risk of a pesticide to human health or the environment. Terrestrial models are used to estimate pesticide concentrations in avian and mammalian food items and exposure and risk to terrestrial organisms from pesticide use. Available models include MCnest (Markov Chain Nest Productivity Model), Screening Imbibition Program (SIP), Screening Tool for Inhalation Risk (STIR), Terrestrial Residue Exposure (T-REX), Terrestrial Investigation Model (TIM), TerrPlant, and T-HERPS.
	Monitoring the Occurrence of Unregulated Drinking Water Contaminants: Occurrence and Reporting Data	This database includes occurrence data for select chemical, viral, and bacterial contaminants suspected to be present in drinking water that do not have health-based standards under the Safe Drinking Water Act (SDWA).
	Monitoring, Assessment and TMDLs	EPA's Region 9 has compiled a set of programs and resources available on monitoring, assessment, and TMDL planning by state and territory.
	Monograph on the Potential Human Reproductive and Developmental Effects of Di(2-Ethylhexyl) Phthalate (DEHP)	NTP-CERHR has prepared a series of monographs on several phthalates. These documents include information on use, exposure, and toxicity.
	Monograph on the Potential Human Reproductive and Developmental Effects of Di-isononyl Phthalate (DINP)	NTP-CERHR has prepared a series of monographs on several phthalates. These documents include information on use, exposure, and toxicity.
	Monograph on the Potential Human Reproductive and Developmental Effects of Di-n-Butyl Phthalate (DBP)	NTP-CERHR has prepared a series of monographs on several phthalates. These documents include information on use, exposure, and toxicity.
	Monographs on the Evaluation of Carcinogenic Risks to Humans Exit	These reports provide information on toxicological effects, chemical-physical properties, production, use, environmental occurrence, general population and occupational exposures, and analytical methods for approximately 400 chemicals that have been identified by the World Health Organization as carcinogenic, probably carcinogenic, or possibly carcinogenic to humans.
	Motor Vehicle Emission Simulator (MOVES) Model	MOVES is an emission modeling system that estimates emissions for mobile sources covering a broad range of pollutants. This tool allows users to perform multiple-scale analysis.
	Multi-Chamber Concentration And Exposure Model (MCCEM)	The MCCEM estimates average and peak indoor air concentrations of chemicals released from products or materials in residential buildings.
	Multimedia, Multipathway, and Multireceptor Exposure and Risk Assessment (3MRA)	The Multimedia, Multipathway, Multireceptor Exposure and Risk Assessment (3MRA) is a screening-level tool that allows the assessment of potential human and ecological health risks resulting from long-term exposure to chemicals related to waste management.
	Multimedia Contaminant Fate, Transport, and Exposure Model (MMSOILS)	The Multimedia Contaminant Fate, Transport, and Exposure Model (MMSOILS) is a screening model to estimate human exposure and risk associated with releases of contamination from hazardous waste sites.
	Multimedia Fate & Transport Modeling: General Information	This webpage provides general information about multimedia fate and transport modeling as well as links to other sources of information on specific models.
	Multimedia Models	This site provides links to five multimedia models maintained by CEAM designed to quantify the movement and concentration of contaminants traveling through groundwater, surface water, and food chain media: Multimedia, Multi-pathway, Multi-receptor Exposure and Risk Assessment (3MRA) system; MINTEQA2 equilibrium speciation model; Multimedia Contaminant Fate, Transport, and Exposure Model (MMSOILS); Multimedia Exposure Assessment Model (MULTIMED); and Watershed Health Assessment Tools Investigating Fisheries (WHATIF) software.
	Nano Titanium Dioxide Environmental Matters: State of the Science Literature Review	This report is a state-of-the-science review of available information on nanosized titanium dioxide (nano-TiO2). Information related to historical and current applications; life cycle; exposure pathways; toxic effects; and sampling and analysis techniques is included.
	Nanomaterial Case Studies: Nanoscale Titanium Dioxide in Water Treatment and in Topical Sunscreen (Final)	This case study report pertains to nanoscale titanium dioxide in water treatment and in topical sunscreen and characterizes the following: life-cycle stages; fate and transport; exposure and dose; human health and ecological effects; and research efforts and needs.
	Nanomaterial Case Study: Nanoscale Silver in Disinfectant Spray (Final Report)	This case study report pertains to nanoscale silver in disinfectant spray and characterizes the following: historical and current applications; physicochemical properties; analytical methods; life-cycle stages; fate and transport in environmental media; exposure and dose; human health and ecological effects; and research needs.
	Nanomaterial Registry (Beta) Exit	The Nanomaterial Registry is an online tool that curates data from existing publically available resources. Data types include physical-chemical properties, biological interaction data, and environmental interaction data for numerous nanomaterials.
	Nanomaterials: Harnessing the Potential, Understanding the Risks	This Science Materials newsletter provides information on the risk of nanomaterials and summary information on nanomaterial research at EPA.
	Nanotechnologies Exit	This website provides general information on nanomaterials including definition and characterization. Addition topics addressed in this resource include how to measure exposure, potential effects to human health and the environment, how to assess risk, and future research needs.
	Nanotechnology & Nanomaterials Research	EPA is developing scientific methods to study and evaluate the unique properties of nanomaterials, how they behave during manufacturing, product use, and end of life disposal. This website provides links to environmental fate of nanomaterials, human health effects research, nanomaterials case studies, and related resources from this website.
	Nanotechnology Consortiums	This website from NIEHS provides information on grantees funded through the Nanotechnology Environmental Health and Safety (Nano-EHS) program. The goals of this program are to gain fundamental understanding on how the physical and chemical properties of ENMs influence their interactions of ENMs with biological systems and to better understand potential health risks associated with ENM exposure.
	National Air Toxics Assessments (NATA)	NATA is EPA's ongoing comprehensive evaluation of air toxics in the U.S. It is a screening tool for state/local/tribal agencies to prioritize pollutants, emission sources, and areas of interest for further study to gain a better understanding of risks.
	National Air Toxics Trends Station (NATTS) Network	The NATTS Network was developed to monitor concentrations and trends in hazardous air pollutants (air toxics) at multiple sites across the U.S. The data can also be used to assess the effectiveness of emission reduction programs, assess and verify air quality models, and can serve as a direct input to source-receptor models.
	National Biomonitoring Program Fact Sheets	These fact sheets from the National Biomonitoring Program summarize exposure and health effects for various substances including: BPA, dioxins, PFCs, phthalates, PAHs, PBDEs and several metals including lead, mercury, arsenic, and cadmium among others.
	National Biomonitoring Program Fact Sheets: Dioxins, Furans and Dioxin-Like Polychlorinated Biphenyls	This resource provides a summary of exposure and health effects of dioxins, furans, and dioxin-like PCBs in the US. Includes links to summary information from other agencies (ATSDR, EPA, FDA, NIH).
	National Biomonitoring Program Fact Sheets: PAHs	This resource provides a summary of exposure and health effects of PAHs in the US. It includes links to summary information from other agencies (ATSDR, EPA, USGS).
	National Biomonitoring Program Fact Sheets: Phthalates	This website provides a summary of exposure and health effects of phthalates in the US and includes links to summary information from other agencies (ATSDR, EPA, FDA, NIH). Some resources are specific to DEHP and DNOP, and others apply to phthalates in general.
	National Biomonitoring Program Fact Sheets: Polycyclic Aromatic Hydrocarbons (PAHs)	This fact sheet contains information on release patterns, environmental fate, and physicochemical properties for BaP.
	National Biomonitoring Program Factsheet: Perfluorochemicals	This CDC fact Sheet includes information on how people are exposed to PFCs, how PFCs effect human health, and levels of PFCs in U.S. population.
	The National Children’s Study (NCS)	This website describes the National Children’s Study (NCS), which was a report that examined the effects of the environment on the growth, development, and health of children across the United States; followed them from before birth until age 21 years; conducted since 2000; studies conducted as part of the NCS included biomonitoring data.
	National Contaminant Occurrence Database (NCOD)	NCOD was developed by EPA in response to the amendments to the Safe Drinking Water Act (SDWA) to house national information on drinking water contaminant occurrence. It is a repository of sample data for both regulated and unregulated contaminants from drinking water sources across the country.
	National Emission Inventory (NEI)	EPA’s NEI database contains information about sources that emit criteria air pollutants and their precursors, and hazardous air pollutants. The database includes estimates of annual air pollutant emissions from point, nonpoint, and mobile sources in the 50 States, the District of Columbia, Puerto Rico, and the Virgin Islands. EPA collects information about sources and releases an updated version of the NEI database every three years.
	National Environmental Methods Index (NEMI) website	The National Environmental Methods Index (NEMI) database lists testing methods in the following categories: chemical, biological, microbiological, toxicity and physical. Also included are sample preparation and processing methods.
	National Estuary Program Guidance	This resource provides guidance on the design, evaluation and implementation of required monitoring for the National Estuary Program, which includes biota.
	National Functional Guidelines for Inorganic Superfund Data Review	This resource includes guidance to determine the usability of analytical data generated through the EPA’s Contract Laboratory Program (CLP) Statement of Work (SOW) ISM01.X Inorganic Superfund Methods (Multi-Media, Multi-Concentration).
	National Guidance: Guidance for Assessing Chemical Contaminant Data for Use in Fish Advisories – Volume 1: Fish Sampling and Analysis	This document provides fish sampling and analysis strategies and procedures. It includes information on selection of target species, selection of target analytes, development of human health screening values, sample collection procedures (e.g., sample processing, sample preservation, and shipping), sample analysis, and data reporting and analysis.
	National Health and Nutrition Examination Survey (NHANES)	CDC's National Health and Nutrition Examination Survey (NHANES) is a program of studies designed to assess the health and nutritional status of adults and children in the United States.
	National Human Adipose Tissue Survey (NHATS)	NHATS is an annual survey conducted from 1970 to 1989 to collect and chemically analyze human adipose tissue specimens for the presence of toxic chemicals.
	National Immunization Survey: Breastfeeding Among U.S. Children Born 2002-2012	This resource is a nationwide survey of breastfeeding practices. Survey results include: percentages of U.S. children who were breastfed by birth year, percentages of breastfed U.S. children supplemented with infant formula by birth year, and tables and maps of breastfeeding rates (by child’s age, state/county, and sociodemographic factors).
	National Lake Fish Tissue Study	The National Lake Fish Tissue Study is a screening-level study conducted to estimate the national distribution of selected persistent, bioaccumulative, and toxic chemicals in fish tissue from lakes and reservoirs of the continental United States. It was conducted between 2000 and 2004 and evaluated 265 chemicals in fish.
	National Lake Fish Tissue Study Analytical Methods Summary	This website describes methods used for chemical analysis of fish tissue samples for the National Lake Fish Tissue Study.
	National Lake Fish Tissue Study Target Analyte (Chemical) List	This website provides a list of target analytes included in the analysis of fish tissue samples for the National Lake Fish Tissue Study.
	National Lakes Assessment	Under the National Lakes Assessment, EPA and its state and tribal partners conducted a survey of the nation's lakes, ponds, and reservoirs to provide national estimates of their condition.
	The National Map Small-Scale Collection	The USGS coordinated development of the National Atlas, which includes electronic climate maps where users can select, preview and print various state and U.S. climate maps.
	National Occupational Exposure Survey (NOES)	The National Occupational Exposure Survey (NOES) conducted between 1981 and 1983 collected data on potential occupational exposures to chemical, physical, and biological agents. The survey involved on-site visits to 4,490 establishments in 522 industry types employing approximately 1,800,000 workers in 377 occupational categories. Nearly 13,000 different potential exposure agents and over 100,000 unique trade name products were observed during these on-site visits.
	National Pesticide Information Retrieval System (NPIRS) website Exit	This website contains information pertaining to pesticides either currently or previously licensed for distribution and sale in the United States and is provided for informational purposes only. An interactive state map is available as a search tool.
	National Population Projections	The U.S. Census Bureau calculates population projections by using “components of population change” data (i.e. births, deaths, and net migration) and assumptions pertaining to fertility and life expectancy. Population projections are estimates of future population counts and thus, differ from population estimates which provide past population counts. The site also contains downloadable data sets related to population demographics.
	National Priorities List (NPL) for Superfund Sites	Waste management facilities on the National Priorities List (NPL) can be viewed from this EPA Office of Superfund website according to user-selected states.
	National Recommended Water Quality Criteria	EPA has developed recommended water quality criteria for the protection of aquatic life and human health in surface water for approximately 150 priority or nonpriority pollutants. The Human Health Criteria Table contains values for consumption of water + organism and organism only. Appendices contain conversion factors for dissolved metals, parameters for calculating hardness-depended dissolved metals, and calculation of freshwater ammonia criterion.
	National Rivers and Streams Assessment (NRSA)	Under this program, EPA and its state, tribal, federal, and other partners conduct a survey to study the conditions of the nation's rivers and streams.
	National Stream Quality Accounting Network (NASQAN)	NASQAN consists of a network of 40 monitoring stations where surface water and sediment samples are collected and analyzed for a broad range of chemicals including pesticides, major ions, and trace elements. This resource also provides concentration and load data for nitrogen, phosphorus, carbon, silica, dissolved solids, selected pesticides, and suspended-sediment discharging from major rivers to U.S. coastal waters.
	National Study of Residues in Fish	This database includes information from a study investigating the prevalence of selected bioaccumulative pollutants in fish and the correlation of these pollutants with potential sources.
	National Survey of Hunting, Fishing, and Wildlife-Associated Recreation	Data shown on this Census website is extracted from the National Survey of Fishing, Hunting, and Wildlife-Associated Recreation (FHWAR), which was conducted by the Census Bureau for the U.S. Fish and Wildlife Service, U.S. Department of the Interior. The data describe fishing, hunting, and wildlife observation activities of resident and nonresident individuals or households for user-selected states.
	National Survey of Pedestrian and Bicyclist Attitudes and Behaviors	The BTS compiles transportation statistics for the nation’s transportation system. This report describes pedestrian and cyclists activities during the summer of 2002. Excel or CVS files for every data table are downloadable.
	National Vital Statistics Report	This CDC report provides information of death, mortality, and life expectancy.
	National Water Quality Assessment (NAWQA) Program	NAWQA provides information on streams, rivers, ground water, and other aquatic systems in support of national, regional, State, and local information needs and decisions related to water quality management and policy.
	National Wetland Condition Assessment	EPA and its partners are implementing a national survey to monitor and analyze the of the Nation’s wetlands.
	Natural Gas Extraction - Hydraulic Fracturing	This website provides information about hydraulic fracturing and any potential impacts on drinking water, groundwater, and air.
	NHANES VOC Dataset Exit	This report provides an introduction to the NHANES project and analyses of the relationship between personal exposures to VOCs and behavioral, socioeconomic, and demographic characteristics. Personal exposures to VOCs among a representative subgroup of participants in NHANES 1999-2001 were measured.
	NOvel Methods for Integrated Risk Assessment of CumuLative Stressors in Europe (NoMiracle) website Exit	NoMiracle develops methods and tools useful for evaluating chemical risks, including cumulative risks to human health and the environment associated with chemical mixtures.
	Nutrient Criteria Technical Guidance Manual: Rivers and Streams	The intent of this document is to provide technical guidance to state and tribal parties on developing region-specific nutrient criteria for river and stream systems and implementing nutrient control strategies.
	Nutrient Pollution Policy and Data	This website provides links to information related to nutrient pollution policy and data, specifically: state development of numeric criteria for nitrogen and phosphorous; tools (e.g., Nitrogen and Phosphorus Data Access Tool, Causal Analysis/Diagnosis Decision Information System [CADDIS]); nitrogen and phosphorous monitoring data; and various reports/resources.
	Nutrient Pollution website	This website provides links to information related to nutrient pollution problems, sources and solutions, effects, and where problems occur, and what you can do in your community, home, yard, and classroom to help address these problems. Also provided is an interactive map with examples of local efforts to reduce nutrient pollution.
	Nutrition During Lactation Exit	This report summarizes research in understanding the relationship between the nutrition of healthy mothers and the outcomes of lactation. Chapter 5 discusses milk volume.
	Nutritional Assistance Program	This resource is entitled "National and state level estimates of the special supplemental nutrition program for women, infants, and Children (WIC) eligibles and program reach, 2000 - 2009 final report (Volume 1). The USDA Food and Nutrition Service (FNS) prepared the Nutritional Assistance Program Report to provide data on the number of women, infants and children (WIC) with low incomes who receive special supplemental nutrition assistance through their program.
	Occupational and Residential Exposure Test Guidelines for Indoor Inhalation Exposure	This document is one of a series of test guidelines that have been developed by the Office of Prevention, Pesticides and Toxic Substances (OPPTS) for use in the testing of pesticides and toxic substances, and the development of test data that must be submitted to the Agency for review.
	Occupational and Residential Exposure Test Guidelines for Outdoor Inhalation Exposure	This document is one of a series of test guidelines that have been developed by the Office of Prevention, Pesticides and Toxic Substances (OPPTS) for use in the testing of pesticides and toxic substances, and the development of test data that must be submitted to the Agency for review.
	Occupational Exposure Sampling Strategy Manual	These technical recommendations outline sampling techniques for personal exposure to air in occupational settings.
	Occupational Pesticide Handler Exposure Data	This resource from contains “unit exposures" (i.e., mass of pesticide active ingredient exposure per unit mass of active ingredient handled—µg/lb ai) for specific combinations of exposure scenario (activity, equipment, formulation, site, etc.), exposure route, and personal protective equipment (PPE) levels.
	Office of Scientific and Technical Information (OSTI) Case Study Comparisons of Vapor Inhalation Risk Estimates	This paper describes two case studies that compare exposure concentrations and estimated human health risks from the RBCA vapor transport models and actual soil vapor concentration and soil vapor flux data. The first case study examines a residential property with petroleum hydrocarbon contamination; the second case study examines chlorinated hydrocarbon contamination in soil and groundwater at a Superfund site. The two approaches compared were the American Society for Testing and Materials (ASTM) Risk-Based Corrective Action (RBCA) model predictions versus site specific soil vapor data.
	Office of Transportation and Air Quality (OTAQ) Modeling and Inventories	This website provides links to mobile source emissions models including MOtor Vehicle Emission Simulator (MOVES), NONROAD model, National Mobile Inventory Model (NMIM), and others. Links are also given for related information including inventories and related non-EPA websites.
	Office of Transportation and Air Quality (OTAQ) website	EPA's Office of Transportation and Air Quality protects public health and the environment by regulating air pollution from motor vehicles, engines, and the fuels used to operate them, and by encouraging travel choices that minimize emissions. These "mobile sources" include cars and light trucks, heavy trucks and buses, nonroad engines, equipment, and vehicles.
	Office of Water website	Information about EPA’s Water Programs can be found at this website.
	Older Adults and Pesticides Exit	This factsheet from NPIC provides information on risks to older adults from exposure to pesticides.
	OncoLogic - A Computer System to Evaluate the Carcinogenic Potential of Chemicals	OncoLogic is a desktop computer program that evaluates the likelihood that a chemical may cause cancer. It is a peer reviewed software that runs on a Windows PC and available at no cost from EPA. Subsystems are available to evaluate fibers, metals, polymers, and more than 48 classes of organic chemicals.
	OnSite: Modeling Subsurface Petroleum Hydrocarbon Transport	This resource provides access to a set of online tools for site assessment including calculators for formulas, models, unit conversion factors, and scientific demonstrations to assess the impacts from ground water contaminants.
	Options for Development of Parametric Probability Distributions for Exposure Factors	This document provides guidance for selecting probability distributions and fitting data from the 1997 edition of the Exposure Factors Handbook for use in probabilistic exposure assessments. Three factors - tap water intake, population mobility, and inhalation rules - are used at test cases in the document. Recommendations on the models that provide the best fit are provided.
	Organic Farming website	This website provides information and guidance related to organic farm produce and links to related resources.
	OSHA Indoor Air Quality website	This OSHA web site provides information on indoor air quality at workplaces. Links to various resources and related topics are provided.
	OSWER Technical Guide for Assessing and Mitigating the Vapor Intrusion Pathway from Subsurface Vapor Sources to Indoor Air	This OSWER guidance provides technical and policy recommendations for evaluation of subsurface vapor intrusion that may occur from subsurface soil and/or groundwater to building indoor air. It describes a recommended framework for assessing vapor intrusion to support risk management decisions. It also provides technical recommendations about monitoring and terminating building mitigation systems.
	Overview of the Ecological Risk Assessment Process in the Office of Pesticide Programs	This 2004 EPA/OPP guidance document contains an overview of the ecological risk assessment process and endangered and threatened species effects determination procedures. The report describes OPP's screening-level and species-specific risk assessment processes for endangered and threatened (listed) species of aquatic life, wildlife, and plants.
	Overview of Perfluorochemicals and Health Exit	This website contains general information on what PFCs are and how exposure occurs.
	Ozone-Depleting Substances (ODS)	This site lists ozone-depleting substances (ODS) categorized by class, number scheme, and global warming potentials for ODS substitutes.
	Paper on Tribal Issues Related to Tribal Traditional Lifeways, Risk Assessment, and Health & Well Being	This report consolidates issues related to risk assessment, health and well-being, and tribal traditional lifeways that have emerged from the various workshops that the National EPA-Tribal Science Council (TSC) has held.
	Particle Total Exposure Assessment Methodology (P-TEAM)	This study was conducted by EPA and the California Air Resources Board to evaluate human exposure to inhalable particulates in the Los Angeles Basin.
	Partnership to Evaluate Flame Retardants in Printed Circuit Boards (Final Report)	This final report addresses the environmental and human health issues associated with the production, use, and disposal of FR4 Printed Circuit Boards using current and emerging flame retardant technologies.
	PCBs: Cancer Dose-Response Assessment and Application to Environmental Mixtures	This archived EPA report describes cancer dose-response assessment for polychlorinated biphenyls (PCBs) and identifies the relevant characteristics that should be considered in evaluating human health risks from PCB mixtures.
	People and Households Data by Subject	The Census Bureau compiles data from several products into more than 40 wide-ranging subject categories, many of which are useful for characterizing potentially exposed populations. They include aspects of daily living (i.e., commuting, computer use, language use, etc.), quality of life measures (i.e., well-being, income, disability, health insurance), general demographics (i.e., age, race and gender), population counts (i.e., births, deaths, migration/immigration, population estimates and projections), and housing and residential characteristics (i.e., family and living arrangements and work at home).
	Perfluorinated Chemical (PFC) Research	This website describes an active research area at EPA to evaluate potential environmental and human health problems associated with release of PFCs into the environment. This research will help to provide the means to estimate human exposures to these materials or establish risks associated with these exposures.
	Permit Compliance System (PCS)	The PCS provides information on permits issued to companies to discharge wastewater into rivers.
	Personal Care Products Council Website Exit	The Personal Care Products Council website has links to information on science and safety, and legislation and regulation of personal care products.
	Pesticide Chemical Search Database	From this website, pesticide chemical searches can be performed using chemical name, cas. no., or PC Code. Searches provide the following information: chemical details regarding pesticide type and registration status/dates; chemical structure; synonyms; and unique chemical identifiers.
	Pesticide Data Program (PDP)	USDA's PDP is a national pesticide residue data program that aids in the management, collection, analysis, and reporting of pesticide residues on agricultural commodities in the U.S. food supply, particularly those consumed by infants and children. Data on drinking water are also collected.
	Pesticide Fact Sheets Exit	This resource includes detailed fact sheets on various pesticide active ingredients, the selection of which was driven by inquiries to the National Pesticide Information Center over a 5-year period.
	Pesticide Industry Sales and Usage Information	This resource provides information on estimating the quantities of pesticides’ active ingredients used and sold in the United States; pesticide imports and exports; and the numbers and types of pesticides in use during specific timeframes.
	Pesticide Information Profiles Exit	Pesticide Information Profiles (PIPs) are documents which provide specific pesticide information relating to health and environmental effects. PIPs are not based on an exhaustive literature search. The information does not in any way replace or supersede the information on the pesticide product labeling or other regulatory requirements. EXTOXNET is a cooperative effort of University of California-Davis, Oregon State University, Michigan State University, Cornell University, and the University of Idaho. Some of the information may be outdated, but the PIPs are often the best collection of information on some more obscure pesticides.
	Pesticide Product Label System (PPLS)	PPLS provides a collection of pesticide product labels is PDF format that have been approved by EPA under Section 3 of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA).
	Pesticide Program Residue Monitoring: 1993-2012	FDA Pesticide Program Residue Monitoring reports are annual reports available for 1993–2012 that contain summaries from the Food and Drug Administration of pesticide residues measured in food. In general, these reports have helped to demonstrate that levels of pesticide residues in the U.S. food supply are well below established safety standards.
	Pesticide Properties Database	The ARS PPD is a compendium of chemical and physical properties that affect pesticide transport and degradation characteristics. It includes data for 334 widely used pesticides.
	Pesticide Reregistration Status	This resource lists registered pesticide active ingredients and provides links to fact sheets that explain the regulatory and toxicological status of the active ingredients.
	Pesticide Use Reporting (PUR) Data	California Department of Pesticide Regulation’s PUR provides data on the use of agricultural pesticides throughout the state. Data are also included on pesticide applications to parks, golf courses, cemeteries, rangeland, pastures, and along roadside and railroad rights-of-way.
	Pesticides	This website provides links to pesticide information related to protecting human health and the environment; pest control; pesticide regulation; pesticide ingredients and products; analytical methods; and other pesticide issues and programs.
	Pesticides in the Diets of Infants and Children Exit	This report addresses the question of whether current regulatory approaches for controlling pesticide residues in foods adequately protect infants and children. The exposure of infants and children and their susceptibility to harm from ingesting pesticide residues may differ from that of adults.
	Pesticides in Ground Water Database (PGWDB): 1971-1991 National Summary	This resource contains summaries of an EPA monitoring program to evaluate pesticides levels in groundwater. Most of the monitoring was conducted in the 1980s. Data in the report are available for wells in 45 states, and wells were tested for over 300 pesticide-related chemicals.
	Pesticides in Selected Water-Supply Reservoirs and Finished Drinking Water, 1999-2000: Summary of Results from a Pilot Monitoring Program	The USGS/EPA Reservoir Monitoring Study was a pilot monitoring program to provide information on pesticide concentrations in drinking water. Drinking water utilities that withdrew water from reservoirs were sampled in 1999 and 2000, and data on pesticide residues were collected.
	Pesticides: Science Policy Issues & Guidance Documents	This resource provides links to information on: FQPA 10-fold safety factor; dietary exposure and risk assessment; threshold of regulation; drinking water exposure; residential exposure; aggregate exposure and risk assessment; cumulative risk assessment for pesticides with a common mechanism of toxicity; cholinesterase inhibition end point; use and usage information. The information and links on this website are no longer updated and may be superseded by current guidance documents.
	Petroleum Hydrocarbons and Chlorinated Hydrocarbons Differ in their Potential for Vapor Intrusion	This report from EPA’s Office of Underground Storage Tanks discusses the impact on the inhalation exposure pathway from vapor intrusion of VOCs.
	Phthalates Action Plan Summary	This website gives a current summary of the status of EPA's action plan for considering the risks from eight phthalates. This page includes links to previous and current actions by EPA towards rulemaking regarding phthalates.
	Phthalates and Cumulative Risk Assessment The Task Ahead Exit	This book provides guidance for assessing the risk of phthalates, chemicals found in many consumer products that have been shown to affect the development of the male reproductive system of laboratory animals. The book suggests an approach for cumulative risk assessment that can serve as a model for evaluating the health risks of other types of chemicals.
	Phthalates and their Alternatives: Health and Environmental Concern Exit	This technical briefing provides an overview of alternatives to phthalates used as plasticizers in a wide range of polyvinyl chloride (PVC) plastic products, with particular emphasis on children’s products. The document describes uses of and products containing phthalates and outlines some of the health and environmental concerns raised regarding these substances.
	Phthalates: Worldwide Environmental Concentrations	This CPSC table provides concentrations of bis (2-ethylhexyl) phthalate in surface water, groundwater, landfill leachate, sediments, soils, air/dust, drinking water, food, sludge, consumer products, wildlife, vegetation, human plasma, and human urine in the United States and around the world.
	Physical Activity; Data and Statistics	This data source provides statistics on physical activity in the United States; information on physical activity behavior and policy and environmental supports by state; and information on surveillance systems that track nutrition, physical activity, obesity, and breastfeeding using surveys and other data collection efforts.
	Physiological Information Database (PID)	Developed in Microsoft ACCESS, this database includes physiological parameters for parameterizing PBPK models for children, adults, and older adults. The Physiological Parameters Database for Older Adults (Beta 1.1) and the Database of Physiological Parameters for Early Life Rats and Mice are included in this final release. The database is available for download and database field descriptions are available in PDF format.
	The Plain English Guide to the Clean Air Act	This site provides information on pollution prevention as it relates to consumer products use. Information on the contribution of consumer products to indoor and outdoor air pollution is provided.
	Plan EJ 2014	This document is a roadmap for integrating environmental justice into the EPA programs, policies, and activities.
	Pocket Guide to Chemical Hazards (NPG)	The NIOSH Pocket Guide to Chemical Hazards presents key information that can be used to recognize and control occupational chemical hazards for several hundred specific chemicals and chemical classes.
	POET Emission Inventory	NASA estimated global emissions of gases (ozone precursors) from anthropogenic, natural, and biomass burning sources for the period 1990-2000. The emissions estimates are based on national activity data and emission factors.
	Policy for Use of Probabilistic Analysis in Risk Assessment	This document is a brief policy statement issued from U.S. EPA which states that probabilistic analysis techniques as Monte Carlo analysis, given adequate supporting data and credible assumptions, can be viable statistical tools for analyzing variability and uncertainty in risk assessments. The statement also defines a set of conditions for acceptance to ensure that good scientific practice in quantifying uncertainty and variability.
	Policy on Evaluating Risk to Children	This policy statement from EPA lays out the position that risks to infants and children should be evaluated differently than risks to adults.
	Pollution Prevention (P2)	This website provides links to pollution prevention (P2) resources, including P2 laws and policies, grant programs for P2, and tools to measure P2.
	Polybrominated Diphenyl Ethers (PBDEs) Action Plan Summary	This website provides a summary of the status of EPA's action plan for considering the risks of PBDEs. This page includes links to previous and current actions by EPA towards rulemaking regarding PBDEs.
	Polychlorinated Biphenyls (PCBs) and Your Health Fact Sheet	This fact sheet provides information on exposure to PCBs including exposure from contaminated air, food, and drinking water.
	Polycyclic Aromatic Hydrocarbon (PAH) Factsheet, 4th Edition Exit	This document contains chemical structures, toxicity occurrence information, and data source links for analytical methods, calibration standards, and other resources.
	Polycyclic Aromatic Hydrocarbons (PAHs): What are the Standards and Regulations for PAHs Exposure?	This ATSDR-supported online course module is focused on describing the OSHA permissible exposure levels and EPA maximum contamination level for PAHs.
	Polynuclear Aromatic Hydrocarbons in Drinking-Water: Background Document for Development of WHO Guidelines for Drinking-Water Quality Exit	This document provides summary-level information on chemical identify, physicochemical properties, and exposure characteristics for PAHs.
	Population and Housing Unit Estimates	The U.S. Census Bureau uses data such as the number of births, deaths, and other components of population change to estimate the number of people and housing units in the United States, individual states, and local areas. This site contains links to the 2012 National, State, and Puerto Rico Commonwealth Total Population Estimates reports.
	Population-Based Methylmercury Exposure Assessment Exit	This study was designed to evaluate fish consumption patterns and mercury body burdens among a representative cross section of Wisconsin's adult population. Subpopulations in Wisconsin that consume fish several times a week and populations that had elevated mercury body burdens are identified and compare current mercury body burdens among Wisconsin residents to national exposure data from CDC's NHANES study are compared. Hair mercury and fish consumption data from this study provide a baseline for future mercury exposure assessments.
	Practical Examples of Exposure Scenarios Exit	This site provides links to several examples of exposure scenarios including those for the semiconductor industry, professional use of a substance in floor coatings, and consumer use of a substance in cleaning products.
	A Preliminary Risk-Based Screening Approach for Air Toxics Monitoring Data Sets (Region 4)	This resource lays out a risk-based methodology for performing an initial screen of air toxics monitoring datasets in outdoor air. The methodology is intended to be simple to perform yet conservative (i.e., health protective) in nature. The screening approach is designed to identify pollutants for which risks are unlikely to be of concern. Pollutants that are above screening level concentrations trigger further evaluation through a more in-depth or refined risk assessment.
	Preparation of Soil Sampling Protocols: Sampling Techniques and Strategies	This document provides guidance for the development of soil sampling protocols, including sampling designs, sample collection, review of background data, methods to reduce sources of sampling error, and data interpretation.
	Principles of Characterizing and Applying Human Exposure Models Exit	This report discusses the characteristics of exposure models and their applications. Different modeling frameworks are examined including a discussion of how deterministic approaches compare to probabilistic approaches. A background document that addresses principles for evaluating exposure models is also included.
	Private Drinking Water Wells	This resource contains links to information and resources regarding private drinking water wells which are not regulated by EPA standards.
	A Probabilistic Exposure Assessment for Children Who Contact CCA-treated Playsets and Decks Using the Stochastic Human Exposure and Dose Simulation Model for the Wood Preservative Scenario (SHEDS-Wood)	EPA refined the SHEDS model (i.e., SHEDS-Wood) to estimate children’s exposure to chromium and arsenic residues from playsets and decks treated with chromate copper arsenate (CCA). The SHEDS model is a probabilistic model that can be used to assess aggregate exposures and multimedia, multipathway chemicals of interest.
	Probabilistic Reverse dOsimetry Estimating Exposure Distribution (PROcEED)	PROcEED is a web-based application used to conduct probabilistic reverse dosimetry calculations. The tool is used for estimating a distribution of exposure concentrations likely to have produced biomarker concentrations measured in a population. PROcEED uses statistical methods to transform the distribution of measured biomarker concentrations to a potential distribution of unmeasured exposure concentrations. This transformation allows scientists to study the causes of exposure. Results can be downloaded as text file or presented graphically. The tool is freely available without a license.
	Process for Assessing Pesticide Risks to Endangered Species	This resource describes EPA's general process for assessing risks to endangered species associated with pesticide exposure. The process includes an effects determination, formal consultation with the U.S. Fish and Wildlife Service and National Marine Fisheries Service, and implementation of measures as necessary to ensure protection of the listed species.
	Product Safety Standards or Guidance	This website provides a lookup table that includes information on the product types for which the Consumer Product Safety Commission (CPSC) “has issued a government mandatory standard, ban or other regulation, or guidance.“
	Provisional Guidance for Quantitative Risk Assessment of Polycyclic Aromatic Hydrocarbons	This provisional guidance provides an approach using weighted potency factors for PAHs. These estimates are recommended only for evaluation of risk from oral exposure and are proposed only for the assessment of potential carcinogenicity of PAHS.
	PRZM3 Model	PRZM3 is a tool that links two subordinate models, PRZM and VADOFT, to predict pesticide transport and transformation down through the crop root and unsaturated zone.
	Public Drinking Water Systems Programs	This website provides links to a variety of public water system programs, resources, and information.
	Pyrethroids and Pyrethrins Assessment	EPA’s Office of Pesticide Programs conducted a cumulative exposure assessment for the pyrethroid pesticides, a family of chemicals with similar neurotoxic modes of action. EPA considered acute and chronic exposure to residues of pyrethroids in food, water, and other potential residential exposures; oral, dermal, and inhalation exposures were considered. The cumulative risk assessment concluded that estimated risks are not of concern.
	Quality Assurance Project Plan for Data Analysis Activities for the National Study of Chemical Residues in Lake Fish Tissue	This report presents performance and acceptance criteria, and quality objectives for the National Fish Tissue Study sample analysis effort.
	Radiation Protection: Technologically Enhanced, Naturally-Occurring Radioactive Materials TENORM in Consumer Products	This website provides information on consumer products that might contain Technologically Enhanced, Naturally-Occurring Radioactive Materials (TENORM), including antiques, building materials, phosphate fertilizer, and tobacco products.
	Radiation Sources and Doses	Information on the sources of radiation is provided at this EPA website.
	RadNet	RadNet, formerly Environmental Radiation Ambient Monitoring System (ERAMS), tracks radiation in the nation’s air, precipitation, drinking water, and milk samples through a nationwide monitoring system.
	Rapid Chemical Exposure Dose Research	This website provides information on the research being conducted using rapid (high-throughput) exposure and dose methodologies.
	Rapid Sediment Characterization Tools	Rapid Sediment Characterization Tools provide guidance on rapid sediment characterization technologies that can be used at marine sediment sites.
	RCRA Waste Sampling Draft Technical Guidance	This guidance was developed by EPA’s Office of Solid Waste and Emergency Response discusses fundamental statistical and “representativeness” concepts behind sampling difficult, heterogeneous materials like soils, sediments, and waste materials. Sampling designs and sampling equipment are discussed.
	REACH Practical Guide on Exposure Assessment and Communication in the Supply Chains; Part IV: Supplement Exposure Estimation Exit	This resource provides guidance to European Union (EU) member countries in estimating occupational and consumer exposure and characterizing risk as part of REACH compliance. Application and evaluation of commonly used exposure assessment tools is also provided.
	ReachScan	ReachScan estimates surface water chemical concentrations at drinking water utilities downstream from industrial facilities. The populations served by the utilities are also estimated and endangered species or critical habitats in the county of the releasing facility are identified. Risk assessors can use chemical concentrations in surface water to estimate fish bioconcentration rates and potential dose rates for humans exposed via ingestion of fish.
	Recognition and Management of Pesticide Poisonings, 6th Edition Exit	This resource details health effects from exposure to many different pesticide active ingredients.
	Region 10 Tribal Programs website	This website provides links to resources for working with tribal governments in in the Pacific Northwest and Alaska.
	Regional Modeling System for Aerosols and Deposition (REMSAD)	REMSAD is used to provide a better understanding of the distributions, sources, and removal processes related to regional haze, particulate matter and other airborne pollutants, including soluble acidic components and toxics. Air concentrations and (wet and dry) deposition values are also available.
	Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) Exit	REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals), a regulation of the European Union (EU), is the European Commission's regulatory system for approximately 30,000 chemical substances. REACH applies to all chemical substances—those used in industrial processes as well as those found in our day-to-day products, such as cleaners, paints, clothes, furniture and electrical appliances. Links to REACH legislation, guidance, nanomaterials, and archives are available at this website.
	Registry of Toxic Effects of Chemical Substances (RTECS)	RTECS is a collection of chemical-specific toxicity data obtained from the scientific literature. Toxicity data files include information relate to: (1) primary irritation; (2) mutagenic effects; (3) reproductive effects; (4) tumorigenic effects; (5) acute toxicity; and (6) other multiple-dose toxicity. Toxicity values such as LD50 and LC50 are also provided.
	Regulating Pesticides: Chromated Copper Arsenate (CCA)	CCA has been used to treat lumber intended for most residential settings, including play structures, decks, picnic tables, landscaping timbers, residential fencing, patios, and walkways/boardwalks. After December 30, 2003, CCA can no longer be used in these products. EPA provides links to various guidance documents and other related topics pertaining to the use of CCA in consumer products.
	The Relationships Among Particle Size, Composition, and Partitioning Phenomena in Aqueous Systems	This effort was conducted by the Colorado School of Mines under agreement with EPA to study the effects of partitioning on the fate, transport, and exposure potential of anthropogenic chemicals in soil and aquatic systems.
	Report to Congress; EPA Studies on Sensitive Subpopulations and Drinking Water Contaminants	This report summarizes EPA's efforts to identify and characterize sensitive subpopulations that may be at a greater health risk from exposure to drinking water contaminants than the general public.
	Report to Congressional Requesters - School Facilities: Conditions of America's Schools	This GAO report describes the condition of school buildings across the nation including the amount of funding needed to correct hazards such as asbestos, lead in water or paint, radon, and materials in underground storage tanks.
	Research on Evaluating Nanomaterials for Chemical Safety	This webpage provides links relevant to nanotechnology research, with focus areas on: types of nanomaterials; chemical safety; potential exposure to nanomaterials; ecological effects; green manufacturing of nanomaterial products; human health effects; life cycle approach; detection, clean up, and pollution prevention; properties and fate and transport; risk assessment; remediation technology; and other nanotechnology research efforts to support sustainable nanotechnology.
	Research on Nanomaterials	This website provides links to various nanomaterial research projects conducted by EPA scientists; collaborative research efforts with universities, foundations, and other partners; and nanomaterial publications.
	A Research Strategy for Environmental, Health, and Safety Aspects of Engineered Nanomaterials Exit	This book presents a strategic approach for developing the science and research infrastructure needed to address uncertainties regarding the potential environmental, health, and safety risks of engineered nanomaterials. The report summarizes the current state of the science and high-priority data gaps on the potential risks posed by engineered nanomaterials and describes the fundamental tools and approaches needed evaluate risk.
	Resource Conservation and Recovery Act (RCRA) Ground Water Monitoring: Draft Technical Guidance	This report provides guidance for implementing groundwater monitoring regulations for regulated units under 40 CFR Part 264 Subpart F, and permitting standards for 40 CFR Part 270. The Draft Technical Guidance also provides compliance guidance for treatment, storage, and disposal facilities for 40 CFR Part 264 Subparts J, K, L, N, and X.
	Respirator Selection Logic Guidance	This document provides guidance to respirator program administrators on respirator selection in accordance with current respirator use and certification regulations and NIOSH policy.
	Respiratory Protection eTool	This OSHA eTool provides guidance on selecting the appropriate respirator, developing a respirator change schedule, and complying with the OSHA respirator standard.
	Results of Section 4 Chemical Testing	In accordance with Section 2(b) of TSCA, summaries of Section 4 chemical tests are provided. Test summary results are presented by chemical name or cas. no and provide the following test information: study type, protocol/guideline, species, exposure type/duration, dose/concentration, no. per group, results, and reference.
	A Review and Analysis of Parameters for Assessing Transport of Environmentally Released Radionuclides through Agriculture	This 1984 report by the Oak Ridge National Laboratory describes an evaluation of parameters used in assessing terrestrial transport of radionuclides through the terrestrial food-chain.
	Review of Emerging Resources: U.S. Shale Gas and Shale Oil Plays	INTEK, Inc. independently developed this report for the U.S. Department of Energy. The report estimates shale gas and shale oil resources and volumes and illustrates their locations on a U.S. map.
	Reviewing New Chemicals under the Toxic Substances Control Act (TSCA)	The TSCA New Chemicals Review Program assists in managing the potential risk to human health and the environment from chemicals new to the marketplace. The program functions to identify conditions, up to and including a ban on production, to be placed on the use of a new chemical before it is entered into commerce.
	Revised Organophosphate Cumulative Risk Assessment (OPCRA)	EPA conducted a cumulative exposure assessment for organophosphate pesticides revising the preliminary cumulative risk assessment conducted in 2001. The preliminary assessment was designed to test and improve method for conducting cumulative risk assessments in the future. The revised assessment evaluated more than 1,000 organophosphate pesticides in food, water, and other potential residential exposures.
	Revised Technical Support Documentation: National-Scale Assessment of Mercury Risk to Populations with High Consumption of Self-Caught Freshwater Fish	This document describes the potential public health hazard (in terms of consumption of contaminated fish) associated with mercury emitted from coal and oil-fired electric utility steam generating units in the United States.
	Revised Universal Soil Loss Equation 2 (RUSLE2)	RUSLE2 is a computer program that estimates rates of rill and interrill soil erosion caused by rainfall and its associated overland flow.
	Risk Assessment for Manufactured Nanoparticles Used in Consumer Products (RAMNUC)	Research on the toxicities of manufactured nano-particles (MNPs) in source materials is being conducted under a grant from the EPA’s National Center for Environmental Research (NCER).
	Risk Assessment Guidance for Superfund (RAGS): Volume I – Part D (Planning and Scoping)	The Risk Assessment Guidance for Superfund (RAGS): Volume I: Part D provides guidance for the use of planning tools developed by the EPA RAGS Part D Workgroup and revised through regional review. The planning tools include a Technical Approach for Risk Assessment (TARA), planning tables, and instructions for using the planning tables.
	Risk Assessment Guidance for Superfund (RAGS): Volume I: Human Health Evaluation Manual (Part A)	The Risk Assessment Guidance for Superfund (RAGS): Volume I: Human Health Evaluation Manual (Part A) provides guidance for evaluating human health effects as part of a baseline risk assessment. This guidance document includes 10 chapters and two appendices describing topics including: planning, data collection and evaluation, exposure and toxicity assessment, and risk characterization.
	Risk Assessment Guidance for Superfund (RAGS): Volume I: Human Health Evaluation Manual (Part E, Supplemental Guidance for Dermal Risk Assessment)	RAGS Volume I, Part E addresses human health risk related to dermal exposures. It incorporates and updates principles of the EPA (1992) interim report, "Dermal Exposure Assessment: Principles and Applications". This guidance does not address dermal exposure to vapors.
	Risk Assessment Guidance for Superfund (RAGS): Volume I: Human Health Evaluation Manual (Part F, Supplemental Guidance for Inhalation Risk Assessment)	This document provides guidance for conducting inhalation risk assessments for Superfund sites.
	Risk Assessment Guidance for Superfund (RAGS): Volume III – Part A, Process for Conducting Probabilistic Assessment	The Risk Assessment Guidance for Superfund (RAGS): Volume III: Process for Conducting Probabilistic Risk Assessment (Part A) provides guidance for using Monte Carlo analysis to characterize variability and uncertainty in human health and ecological risk assessments. This guidance document includes 7 chapters and 8 appendices describing topics including: probabilistic analysis, communicating risks and uncertainties, sensitivity analysis, and advanced modeling approaches.
	The Risk Assessment Information System (RAIS)	This website from ORNL provides links to information on performing risk assessments that complies with EPA guidance. Chemical-specific data are available including toxicity profiles, toxicity values, and chemical data profiles.
	Risk Assessment of Combined Exposure to Multiple Chemicals: A WHO/IPCS Framework. Regulatory Toxicology and Pharmacology 60 (2: S1)	This resource describes the WHO/IPCS prioritization framework resulting from a workshop on aggregate and cumulative risk assessment. The framework uses a hierarchy to organize approaches according to refinement, taking into account both exposure and hazard. Predictive and probabilistic techniques, uncertainty, and real world applications are discussed in this document.
	Risk Management of Installations and Chemicals: Perfluorooctane Sulfonate (PFOS) and Related Chemical Products Exit	This website provides information on a hazard assessment of PFOS and its salts including a link to the results of the survey the production and use of PFOS, PFOA, PFAS, PFCA, their related substances chemicals and products/mixtures containing these substances. The study results provide concentration data for PFOA.
	RISK, Indoor Air Quality Model	The RISK model allows calculation of individual exposure to indoor air pollutants from sources. RISK runs in the MS-Windows operating environment and allows users to calculate risk based on the calculated exposure.
	Risk-Based Corrective Action (RBCA) Fate and Transport Models: Compendium and Selection Guidance	This report, a joint effort between EPA and ASTM, catalogs and describes non-proprietary fate and transport models. It is designed to assist users in selecting a model.
	River and Stream Water Quality Model (QUAL2K) Exit	QUAL2K (or Q2K) is a river and stream water quality model that can be used to assess the environmental impact of multiple pollution discharges along rivers from point and nonpoint sources.
	Safe Drinking Water Information System (SDWIS)	EPA’s Safe Drinking Water Information System (SDWIS) databases store information submitted by the states, EPA regions, and drinking water systems to ensure compliance with the Safe Drinking Water Act (SDWA).
	Safe Food Handling Fact Sheets	This resource provides information and recommendations for handling food safely.
	Safe Production and Use of Nanomaterials Exit	The NANOSAFE project is a consortium effort funded by the European Community Competitive and Sustainable Growth Program, The first NANOSAFE effort focused on technical analysis of industrial applications of nanomaterials, while NANOSAFE2 (ongoing) is focused on develop risk assessment and management for secure industrial production of nanoparticles. The website features dissemination reports, critical literature reviews, news updates, and conference reports.
	SAFENANO website Exit	This website is the home of the ENPRA project, which is a European Framework 7 project to develop and implement a novel integrated approach for engineered nanoparticle risk assessment. It was a 3.5 year project with 15 European and 6 US partners that ended in September 2012.
	Safer Chemicals Research	This website provides links to methods, models, tools, and databases related to chemical safety research.
	Sampling House Dust for Lead: Basic Concepts and Literature Review	This report provides background information for standardizing house dust sampling techniques for lead. A literature review and a discussion of house dust sampling methods are included.
	School Enrollment Data	Data and statistics describing school enrollment by age, race, employment, etc., are presented for students enrolled in school programs, including nursery, elementary and high schools, college and university, and professional degrees. This site contains links for the 2010 and 2011 school enrollment reports, as well as a January 2013 working paper entitled “The Decline in Private School Enrollment.”
	Science and Decisions: Advancing Risk Assessment. Washington, DC, National Academies Press Exit	This resource makes practical scientific and technical recommendations to address challenges related to risk assessment, including improving uncertainty and variability analysis, giving greater attention to planning, scoping, and problem formulation, and developing criteria for applying defaults. Chapter 4 of Science and Decisions addresses the use of probabilistic assessments to quantify and qualify uncertainty and variability. Chapter 5 provides suggestions on methods to employ probabilistic approaches to dose-response assessments.
	Science and Ecosystem Support Division (SESD) Soil Sampling Operating Procedures	This EPA Region 4 manual describes procedures, methods, and considerations for collecting soil samples for field screening or laboratory analysis.
	Science and Technology: Land, Waste, and Cleanup Science	This website provides links to information and additional resources regarding EPA's research to protect human health and the environment in support of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), and the Resource Conservation and Recovery Act (RCRA).
	Science and Technology: Water Science	This website provides information on EPA projects and activities related to support of the Clean Water Act and Safe Drinking Water Act.
	Science in Indian Country website	This EPA website provides links to resources relevant to tribes including the Tribal Science Council, Tribal-Focused Environmental Risk and Sustainability Tool (T-FERST), and information on tribal science priorities.
	Scientific Opinion on Emerging and Novel Brominated Flame Retardants (BFRs) in Food Exit	This opinion paper contains information on 17 “emerging” BRFs and 10 “novel” BFRs and identifies which of these substances are potential health concerns based on occurrence, exposure, and toxicity data.
	Scientific Opinion on Polybrominated Diphenyl Ethers (PBDEs) in Food Exit	This opinion paper contains information on PBDE occurrence, exposure, and toxicity.
	Scientific, Technical, Research, Engineering and Modeling Support Final Report State of the Science Literature Review: Everything Nanosilver and More	This final report summarizes available information on silver nanomaterials and includes information related to historical and current applications; uses; synthesis and properties; life cycle; environmental exposure; toxicity and health effects; and data needs.
	Screening Information Data Set (SIDS): Melamine Exit	This SIDS report for melamine contains physicochemical properties and general exposure information.
	Screening Tool for Inhalation Risk (STIR)	The STIR model is designed to be a screening tool in the problem formulation phase of risk assessments for evaluating potential risk from inhalation. The model incorporates the toxicity, application rate, and physical properties of a specific chemical.
	Selection Criteria for Mathematical Models Used in Exposure Assessments (Groundwater Models)	This document is designed to help the exposure assessor evaluate the appropriateness of models for various situations. The report defines the terms and discusses the general approaches used in modeling so that exposure assessors can evaluate the appropriateness of both new and existing models.
	Selection Criteria for Mathematical Models Used in Exposure Assessments (Surface Water Models)	This document is designed to help the exposure assessor evaluate the appropriateness of models for various situations. The report defines the terms and discusses the general approaches used in modeling so that exposure assessors can evaluate the appropriateness of both new and existing models.
	Simulation Tool Kit for Indoor Air Quality and Inhalation Exposure (IAQX), Version 1.0 User’s Guide	This resource is a comprehensive guide to using IAQX version 1.
	The Sister Study	The Sister Study is an evaluation of 50,000 sisters of women diagnosed with breast cancer in the United States to identify risk factors including chemical exposure as measured by biomonitoring.
	Site Evaluation for Dioxin at Superfund Sites	This website provides links to documents relevant to site evaluation of dioxin at Superfund sites, including guidance documents related to dioxin sampling and analytical methods for dioxin. Guidance documents include: Guidance on Systematic Planning Using the Data Quality Objectives Process; Guidance on Choosing a Sampling Design for Environmental Data Collection for Use in Developing a Quality Assurance Project Plan; User Guide - Uniform Federal Policy Quality Assurance Project Plan Template For Soils Assessment of Dioxin Sites; and Template - Uniform Federal Policy Quality Assurance Project Plan For Soils Assessment of Dioxin Sites.
	Sociodemographic Data Used for Identifying Potentially Highly Exposed Populations	This document provides guidance to help risk and exposure assessors identify and enumerate populations that may potentially experience greater contact with environmental contaminants due to unique activity patterns, preferences, behaviors and various sociodemographic characteristics.
	Soil and Sediment Sampling Methods	EPA’s National Exposure Research Laboratory in Las Vegas, NV has led several efforts aimed at addressing issues concerning sampling of contaminated soils and sediments. The main objective of this effort is to provide state-of-the-art guidance, strategies, and techniques for the collection of environmental samples.
	Soil Bioavailability at Superfund Sites	EPA’s Superfund office created a web page that contains basic information about bioavailability and provides links to a series of guidance documents and other efforts aimed at addressing bioavailability of chemicals in soils and sediments.
	Soil Fumigant Toolbox	The Soil Fumigant Toolbox provides resources (e.g., chemical summaries, fact sheets, label information, fumigant management plans, buffer zones and tarps) for applicators and handlers, communities, state and local agencies, and other interested parties in understanding and implementing the current requirements for safe use of soil fumigants.
	Soil Sampling Quality Assurance User’s Guide	This resource includes methods and procedures for establishing adequate quality assurance on soil sampling aspects of environmental monitoring programs.
	Soil Screening Guidance	The Soil Screening Guidance is a framework proposed by U.S. EPA for developing risk-based, soil screening levels for protection of human health. The framework presents a tiered approach for site evaluation and screening-level development.
	Soil Survey Geographic Database (SSURGO)	The Natural Resources Conservation Service (NRCS) developed the SSURGO database to house information about soil properties (including chemical properties) for soils of the United States.
	Soil Taxonomy	This resource provides a link to the second edition of Soil Taxonomy, A Basic System of Soil Classification for Making and Interpreting Soil Surveys, including maps and other soil resources.
	Source Ranking Database	The Source Ranking Database includes preliminary screening-level reviews of over 12,000 potential indoor pollution sources and allows for the identification of high-priority product and material categories for further evaluation.
	SPECIATE Database	SPECIATE is EPA's repository of total organic compound (TOC) and particulate matter (PM) speciation profiles of air pollution sources. The database can be used to create speciated emissions inventories for air quality modeling, estimate hazardous and toxic air pollutant emissions from total PM and TOC primary emissions, provide input to chemical mass balance receptor models, and verify profiles derived from ambient measurements using multivariate receptor models (e.g., factor analysis and positive matrix factorization).
	Spreadsheet-based Ecological Risk Assessment for the Fate of Mercury (SERAFM)	SERAFM is a process-based, steady-state modeling system that predicts speciated mercury concentrations (Hg0, HgII, MeHg, HgT) in water (filtered and unfiltered) and sediments, and total mercury concentrations in fish tissue.
	Standard Method for the Testing and Evaluation of Volatile Organic Chemical Emissions from Indoor Sources Using Environmental Chambers Exit	This California Department of Health document describes standard practice guidelines for testing VOC emissions in indoor environments.
	Standard Operating Procedures (SOPs) for Residential Pesticide Exposure Assessment	The 2012 Residential SOPs are based on the Guidelines for Exposure Assessment and present scenario-based assessments of exposure to pesticides in residential settings. New scenarios have been added to this edition for new products and uses; exposure algorithms for some existing exposure scenarios have been modified. Links to spreadsheets that can be used to perform the calculations are also available from this resource.
	Standards by Category Exit	ASTM International (formerly known as the American Society for Testing and Materials, or ASTM) develops and provides support related to international voluntary consensus standards. Standards developed by ASTM include those relevant to occupational settings, including industrial hygiene and safety standards that specify methods for measuring the presence and amounts of chemical hazards used in the workplace. ASTM has also developed consumer product and related standards that cover methods for measuring chemicals related to a wide range of products.
	State and County QuickFacts	The Census QuickFacts website contains a tool that allows users to select, view, and compare national, state, and available county/city statistics for the current and previous year. A one page table of summarized data is produced that lists population, business, and geography statistics (using numbers or percentages). This is an easy to use, intuitive tool.
	State Facts for Students	This site summarizes data from the 2010 census considered to be of interest for students age 8-12. Some information is relevant for characterizing exposures such as the state’s population of boys and girls, largest city, and the number of certain businesses such as fast food restaurants.
	Statistical Abstract of the United States	The 2012 Statistical Abstract provides a comprehensive data summary of housing, neighborhood, building, energy, utilities, health, nutrition, labor, income, expenditures, activities, highway mileage, social and many other attributes which characterize the conditions of the United States populations presented by various demographic breakdowns. It contains data from government and private sources, focusing on national data but also providing some regional and state level data. Data is available in a hard-copy report and via the Census website where the contents can be searched, viewed, downloaded, or printed.
	Statistical Abstract – Energy and Utilities	The U.S. Census Bureau 2012 Statistical Abstract provides data on energy production and use, including statistics pertaining to fuel resources such as electric, hydroelectric, nuclear, solar wood and gas. Drinking and sewage water statistics are also available from this site.
	Statistical Abstract: Highway Mileage by State - Functional Systems and Urban/Rural: 2009	The Census 2012 Statistical Abstract provides a comprehensive data summary of housing, neighborhood, building, energy, utilities, health, nutrition, labor, income, expenditures, activities, highway mileage, social and many other attributes which characterize the conditions of the United States populations presented by various demographic breakdowns. This site links specifically to data tables for highway mileage by state.
	Statistical Analysis of Groundwater Monitoring Data at Resource Conservation and Recovery Act (RCRA) facilities: Unified Guidance	The Unified guidance suggests recommendations for the statistical analysis of groundwater monitoring data at RCRA units under 40 CFR Part 264, 265, and 258.
	Statistics about Non-Public Education in the United States	This U.S. Department of Education website provides non-public school statistics such as the number of private and home-schooled children in America.
	Stochastic Human Exposure and Dose Simulation (SHEDS)	The Stochastic Human Exposure and Dose Simulation (SHEDS) is a model that can be used to simulate chemical exposures for a population over time. This model estimates exposure for a variety of multimedia and multipathway environmental chemicals and has been modified for use in specific exposure scenarios (e.g., SHEDS-Wood and SHEDS-Pesticides). Other SHEDS modules have been developed to address toxic chemicals in the air (SHEDS-ATOX) and to predict exposures to particulate matter (SHEDS-PM). SHEDS-Multimedia includes the SHEDS-Residential and SHEDS-Dietary modules.
	Storage and Retrieval for Water Quality Data (STORET)	The STORET Data Warehouse is a repository for water quality, biological, and physical data collected by water resource management groups across the country.
	Stormwater Management Model (SWMM)	The EPA Storm Water Management Model (SWMM) is a dynamic rainfall-runoff simulation model used for single event or long-term (continuous) simulation of runoff quantity and quality from primarily urban areas.
	Study of Children’s Activity Patterns. California Environmental Protection Agency, Air Resources Board Research Division. Sacramento, CA	This report presents the results of a large-scale survey of children's activity patterns in California. Time spent in various locations and performing various activities was used to estimate potential exposure to air pollutants. Results are reported by age, gender, region, and season.
	Substance Registry Services (SRS)	SRS is a central information system about chemicals, biological organisms, and other substances that are tracked or regulated by EPA. Each substance has a record that provides basic information about the chemical or biological organism, identifies standardized nomenclature and synonyms used by EPA, and provides available links to fact sheets or other substance-related documentation. Substance queries are performed using substance name or synonym or a substance identifier (such as cas. no).
	Summary Report for the Workshop on Issues Associated with Dermal Exposure and Uptake	This report summarizes a workshop focused on four key areas of concern: estimating dermal absorption from water, estimating dermal absorption from soil, the use of oral-dermal toxicity adjustment factors, and dermal risk characterization/uncertainty. In each of these areas, the participants attempted to identify and categorize three kinds of issues: (a) those which should be addressed in the finalization of the current dermal guidance, (b) those which should be given immediate attention by the agency before any future dermal guidance is prepared, and (c) those which should serve as the basis for an ongoing research program to improve the accuracy and breadth of applicability of dermal risk assessment methodologies.
	Summary Report of a Peer Involvement Workshop on the Development of an Exposure Factors Handbook for the Aging	This report provides an overview of a meeting held February 14-15, 2007 which was organized to discuss factors affecting exposures of older adults to environmental chemicals, as well as issues related to the development of an exposure factors handbook for the aging.
	Summary Report of the U.S. EPA Colloquium on Soil/Dust Ingestion Rates and Mouthing Behavior for Children and Adults	This resource provides a discussion of issues related to soil and dust ingestion rates.
	Superfund Analytical Services / Contract Laboratory Program (CLP)	This document is designed to offer the data reviewer guidance in determining the usability of analytical data generated through the U.S. EPA Contract Laboratory Program (CLP).
	Superfund Chemical Data Matrix	The Superfund Chemical Data Matrix provides Hazard Ranking System (HRS) factor values, screening concentration benchmarks, and chemical/physical properties for hazardous substances frequently found at sites evaluated using the HRS.
	Superfund Contaminated Sediments: Guidance Documents, Fact Sheets and Policies	This web page provides guidance documents, fact sheets, and policies relating to contaminated sediments at Superfund sites.
	Superfund Sediment Resource Center	The Superfund Sediment Resource Center (SSRC) is designed to provide consultation and expert advice to EPA staff for the characterization and cleanup of contaminated sediment sites. Areas of focus for the SSRC include modeling (hydrodynamic, fate and transport, food chain).
	Superfund Soil Screening Guidance	The Soil Screening Guidance is a framework proposed by U.S. EPA for developing risk-based, soil screening levels for protection of human health. The framework presents a tiered approach for site evaluation and screening-level development. Appendix G provides information on uptake of contaminants to plants from soil.
	Supplemental Guidance for Assessing Susceptibility From Early-Life Exposure to Carcinogens	This document includes EPA's recommendations to Agency risk assessors preparing cancer risk assessments and in particular the consideration of childhood risks.
	Supplemental Guidance for Developing Soil Screening Levels for Superfund Sites	The supplemental guidance is a companion guide to the Soil Screening Guidance and describes additional scenarios for soil screening evaluations for residential land use. It also updated the residential scenario presented in the original guidance, adding exposure pathways and incorporating new modeling data. The 2002 version includes updated dispersion modeling data for the residential air exposure model and new methods to develop SSLs for the migration of volatiles from subsurface sources into indoor air that supersede the 1996 guidance.
	Supplementary Guidance for Conducting Health Risk Assessment of Chemical Mixtures	This supplemental guidance document details principles and procedures mentioned but not thoroughly explained in 1986 Guidelines for the Health Risk Assessment of Chemical Mixtures.
	Support Center for Regulatory Atmospheric Modeling – Air Quality Models	EPA’s Air Quality Modeling group maintains this site with documentation, guidance, and model code for dispersion, photochemical, and receptor models commonly used to support policy and regulatory decisions, including the assessment of control strategies and source impacts. Preferred/recommended dispersion models include the AERMOD Modeling System and the CALPUFF Modeling System. Links are provided to several photochemical models: Community Multi-scale Air Quality (CMAQ); Comprehensive Air quality Model with extensions (CAMx); Regional Modeling System for Aerosols and Deposition (REMSAD); and Urban Airshed Model Variable Grid (UAM-V®) as well as receptor models: Chemical Mass Balance (CMB); UNMIX; and Positive Matrix Factorization (PMF).
	Surfacewater Models	The EPA CEAM Surfacewater Models site provides links to 15 surface water models designed to quantify movement and concentration of contaminants in lakes, streams, estuaries, and marine environments: Environmental Fluid Dynamics Code (EFDC); Exposure Analysis Modeling System (EXAMS); EXAMS - PRZM Exposure Simulation Shell (EXPRESS); Green Cross Solar (GCSOLAR) program; Hydrodynamic, Sediment, and Contaminant Transport Model (HSCTM2D); Hydrological Simulation Program - FORTRAN (HSPF); Pesticide Root Zone Model (PRZM3); River and Stream Water Quality Model (QUAL2K); Revised Universal Soil Loss Equation 2 (RUSLE2); Spreadsheet-based Ecological Risk Assessment for the Fate of Mercury (SERAFM) modeling system; Storm Water Management Model (SWMM); Virtual Beach (VB); Visual Plumes modeling system; Water Quality Analysis Simulation Program (WASP); and Watershed Health Assessment Tools Investigating Fisheries (WHATIF) software.
	SW-846 Test Methods website	This on-line resource provides access to EPA’s “Test Methods for Evaluating Solid Waste, Physical/Chemical Methods", also called “SW-846.” These methods for analytical chemistry and characteristic testing methodologies, environmental sampling and monitoring, and quality assurance support the Resource Conservation and Recovery Act (RCRA) program and other hazardous waste programs.
	Swimmer Exposure Assessment Model (SWIMODEL)	SWIMODEL is a screening tool to conduct exposure assessments of pesticides found in indoor swimming pools and spas.
	TANKS Model	TANKS is a Windows-based computer software program that estimates volatile organic compound (VOC) and hazardous air pollutant (HAP) emissions from fixed- and floating-roof storage tanks.
	Technical Guide 230: Environmental Health Risk Assessment and Chemical Exposure Guidelines for Deployed Military Personnel Exit	Technical Guide 230 provides information on chemical warfare agents, toxic industrial agents, and general environmental pollutants as chemical hazards and outlines the risk assessment methods, evaluation, and exposure communication guidance for military personnel response to air, water, and soil chemical exposure. The guidance document aims to reduce occupational and environmental exposure to hazards and chemicals as well as the potential of exposure during military operations. The guidance also aids in reducing immediate and long-term health effects of exposed individuals.
	Technical Manual on Ventilation	This OSHA manual provides technical information and guidance on occupational safety and health issues and can be used by OSHA Compliance Safety and Health Officers to assist in hazard recognition and provide guidance in accident prevention.
	Technical Manual, Section II, Chapter 1: Personal Sampling for Air Contaminants	These OSHA guidelines provide information on monitoring requirements and methods for various chemicals.
	Technical Support Document (TSD) Volume 2: Development of National Bioaccumulation Factors	The TSD Volume 2: Development of National Bioaccumulation Factors documents EPA's methodology for developing national bioaccumulation factors (BAFs) used for deriving national recommended ambient water quality criteria.
	Technical Support Document (TSD) Volume 3: Development of Site-Specific Bioaccumulation Factors	The TSD Volume 3: Development of Site-Specific Bioaccumulation Factors (BAFs) provides technical details on how to develop site-specific bioaccumulation factors (BAFs) for use in deriving ambient water quality criteria. It includes guidance on different approaches as well as factors to consider when selecting an approach to allow states and tribes to derive BAFs that are more representative of the bioaccumulation potential at a given location.
	Technology Transfer Network (TTN)	This resource provides links to various web sites related to air pollution, including resources for air quality monitoring, modeling, fate exposure and risk analysis (FERA), policy and guidance.
	Technology Transfer Network (TTN) Air Toxics: Cyanide Compounds	This TTN website provides a hazard summary for cyanide compounds and includes information uses, sources of potential exposure, and hazard information.
	Technology Transfer Network (TTN) Air Toxics: Dibutyl Phthalate	This website provides a hazard summary of phthalates (BHP, DEHP) including uses, sources and exposure, health hazards, and physical properties.
	Technology Transfer Network (TTN) Support Center for Regulatory Atmospheric Modeling (SCRAM)	This Web site is maintained by EPA’s Air Quality Modeling Group (AQMG) and provides links to various air quality models, such as dispersion models, photochemical models, and receptor models. It also provides additional resources such as modeling applications and tools, and documentation and guidance for air quality models.
	Technology Transfer Network (TTN) Support Center for Regulatory Atmospheric Modeling (SCRAM) – Observational Meteorological Data	Observed meteorological data are used in air quality modeling to capture the atmospheric conditions occurring at a source and/or receptor location and play an important role in identifying the concentration of pollutants at receptors of interest. These meteorological data include physical parameters measured by instrumentation: temperature, dew point, wind direction, wind speed, cloud cover, cloud layer(s), ceiling height, visibility, current weather, and precipitation amount.
	Technology Transfer Network (TTN): Clearinghouse for Inventories & Emissions Factors (CHIEF)	This web site provides links to emissions inventories, air quality emission factors from the Emissions Factors and Policy Applications Center (EFPAC), Emissions Modeling Clearinghouse (EMCH), and monitoring techniques for air pollution control.
	Terrestrial Investigation Model (TIM)	TIM is a probabilistic model that estimates the probability, magnitude, and certainty of risk to terrestrial organisms from exposure to pesticides.
	Test Guidelines for Pesticides and Toxic Substances	A series of harmonized test guidelines has been developed to use in the testing of pesticides and toxic substances. This compilation of guidelines has been developed for conducting the studies routinely used for generating data on pesticides and industrial chemicals regulated under FIFRA and TSCA.
	Test No. 427: Skin Absorption: In Vivo Method. In: OECD Guidelines for the Testing of Chemicals, Section 4: Health Effects Exit	This document provides OECD test guidelines for measuring dermal absorption and delivery of a test substance using human or animal skin.
	Test No. 428: Skin Absorption: In Vitro Method. In: OECD Guidelines for the Testing of Chemicals, Section 4: Health Effects Exit	This document provides OECD test guidelines for measuring dermal absorption and delivery of a test substance using human or animal excised skin.
	Three Technology Revolutions: Teens Exit	Description: The Pew Research Center is a nonprofit, nonpartisan group that supplies data on the issues, attitudes, and trends influencing America. This website provides links to teen internet user demographics, internet use over time, social media use over time, and device ownership over time.
	A Tiered Modeling Approach for Assessing the Risks Due to Sources of Hazardous Air Pollutants	This resource is divided into three main sections that provide guidance on a tiered approach to assessing risks from hazardous air pollutants. The screening level approach (i.e., Tier 1) is a simple method for estimating concentrations without specific source knowledge. The second tier is a more sophisticated screening technique that requires some source-specific knowledge and the third tier involves site-specific computer simulations.
	Tools for Schools	Indoor air quality (IAQ) Tools for Schools provides guidance and links to additional resources for indoor air quality in schools.
	Total Diet Study (TDS)	The Total Diet Study (TDS) is an ongoing FDA program that determines levels of various contaminants, including pesticide residues, and nutrients in foods. This website provides an overview of FDA's TDS and access to analytical results (data summaries as well as individual results for each food) from mid-1991 to the present.
	Total Exposure Assessment Methodology (TEAM) Study	EPA designed this study to develop methods to measure individual total exposure (through air, food, and water) to toxic and carcinogenic chemicals, including VOCs, pesticides, and carbon monoxide. Breath, personal air, outdoor air, and water samples were collected for 30 VOCs.
	Total Risk Integrated Methodology (TRIM) – TRIM.FaTE	The TRIM.FaTE model estimates movement and transformation of pollutants over time. Outputs provide exposure estimates for environmental and human receptors that can be used in other models.
	ToxCastDB	This tool is designed with the ultimate goal to relate human disease to chemical exposure, ToxCastDB links biological, metabolic, and cellular pathway data to gene and in vitro assay data for chemicals. Human disease and species homology information is used to correlate with ToxCast assays that affect specific genetic loci. Users can search by chemical name or cas. no. ToxCastDB can link to the available animal data in ToxRefDB, and the database allows for statistical analysis/outputs.
	Toxic Metals	This website from OSHA provides general information on occupational exposure to metals and common sources of exposure to arsenic, beryllium, cadmium, hexavalent chromium, lead, and mercury. Additional information for other metals (e.g., cobalt, nickel, copper) is also available from this website including exposure risks, exposure limits, and health effects.
	Toxicity Criteria Database	The OEHHA Toxicity Criteria Database is searchable by chemical name, cas. no., or use and provides the following information, as available, for chemicals: uses, list of synonyms, Acute Reference Exposure Levels, Chronic Reference Exposure Levels, California Public Health Goals, Proposition 65 No Significant Risk Levels (NSRLs) and Maximum Allowable Daily Levels (MADLs), and cancer potency information.
	Toxicological Benchmarks for Screening Contaminants of Potential Concern for Effects on Sediment-Associated Biota: 1997 Revision	This document presents toxicological benchmarks for sediment-associated biota in marine, estuarine, and freshwater environments.
	Toxicological Benchmarks for Screening Potential Contaminants of Concern for Effects on Aquatic Biota: 1996 Revision	This document presents toxicological benchmarks for protection of aquatic life from contaminants in water and describes methods for deriving these benchmarks.
	Toxicological Profile for Phosphate Ester Flame Retardants	This report characterizes the toxicological and adverse health information for phosphate ester flame retardants, including summary-level data on physical chemical properties, population exposure levels, and exposure routes.
	Toxicological profile for Polybrominated Biphenyls (PBBs) & Polybrominated Diphenyl Ethers (PBDEs)	Toxicological Profiles contain a review of key studies and other data characterizing the exposure-related health effects and pertinent characteristics and processes that affect human exposures. Sections include other relevant information on releases to the environment, environmental fate, levels monitored in the environment, potential exposures, and analytical methods.
	Toxicological Profile for Polychlorinated Biphenyls (PCBs)	Toxicological Profiles contain a review of key studies and other data characterizing the exposure-related health effects and pertinent characteristics and processes that affect human exposures. Sections include other relevant information on releases to the environment, environmental fate, levels monitored in the environment, potential exposures, and analytical methods.
	Toxicological Profile for Polycyclic Aromatic Hydrocarbons	Toxicological Profiles contain a review of key studies and other data characterizing the exposure-related health effects and pertinent characteristics and processes that affect human exposures. Sections include other relevant information on releases to the environment, environmental fate, levels monitored in the environment, potential exposures, and analytical methods.
	Toxicological Profile for Total Petroleum Hydrocarbons	This document characterizes the toxicological and adverse health information for total petroleum hydrocarbons, including summary-level data on population exposure levels and exposure routes.
	Toxicological Profiles for Hazardous Substances	ATSDR has prepared approximately 300 toxicological profiles for hazardous substances found at National Priorities List (NPL) sites and other federal sites. Chemical names may be searched using the A to Z list on the ATSDR Toxic Substances Portal. Each Toxicological Profile contains a review of key studies and other data characterizing the exposure-related health effects and pertinent characteristics and processes that affect human exposures. Sections include other relevant information on releases to the environment, environmental fate, levels monitored in the environment, potential exposures, and analytical methods.
	Toxicological Review of Trichloroethylene	The IRIS database contains information on more than 550 chemical substances and the human health effects that might result from exposure to these substances. IRIS chemicals with a toxicological review include a review of PBPK models when available. The 2011 final toxicological review for trichloroethylene (TCE) describes and evaluates TCE PBPK modeling efforts and discusses their utility in predicting internal dose. Other IRIS toxicological reviews that evaluate PBPK models include 1,4-Dioxane, Carbon Tetrachloride, Ethylene glycol monobutyl ether (EGBE), Chloroprene, Dichloromethane.
	Toxicology Data Network (TOXNET)	Toxicology Data Network (TOXNET) provides links to databases on toxicology, hazardous chemicals, environmental health, and toxic releases, including: Carcinogenic Potency Database (CPDB); ChemIDplus; Comparative Toxicogenomics Database (CTD); Hazardous Substances Data Bank (HSDB); Toxicology Literature Online (TOXLINE); Chemical Carcinogenesis Research Information System (CCRIS); Developmental and Reproductive Toxicology (DART); GENE-TOX; Integrated Risk Information System (IRIS); International Toxicity Estimates for Risk (ITER); LactMed; Toxics Release Inventory (TRI); Haz-Map; Household Products Database (HPD); and TOXMAP.
	Toxics Release Inventory (TRI)	The TRI database compiles data on toxic chemical releases and waste management activities reported annually by certain industries as well as federal facilities. The data are made available through data files and database tools. Summary data for over 600 chemicals are available by chemical name or CAS Registry Number.
	ToxRef Database	This page provides a link to ToxRefDB. ToxRefDB is a repository for in vivo animal toxicity study data with information on study design, dosing, and observed treatment-related effects. Detailed study and effect information is available for 474 chemicals, primarily pesticide active ingredients. ToxRefDB is searchable by chemical name, cas. no., and endpoint.
	Traffic Congestion and Reliability: Trends and Advanced Strategies for Congestion Mitigation	This report names the U.S. cities with major traffic congestion, identifies the causes and measurements of traffic congestion, and discusses congestion relief strategies.
	Transportation and Air Quality	EPA’s Office of Transportation and Air Quality (OTAQ) homepage provides information on transportation-related sources of air pollution.
	U.S. Counties website	Data from several Census products (including 2010 population and housing data) are combined to form this easy to use data lookup tool where users can query, view, download, and print statistics for more than 6,600 data items. Users can select counties and states of interest as well as national data for several general topics relating to population, demographics, business services, government functions, health, trade and industry, etc. Excel spreadsheets can also be downloaded from the site.
	U.S. EPA Analysis of Survey Data. Commercial Buildings Energy Consumption Survey (CBECS)	The Commercial Buildings Energy Consumption Survey (CBECS) collects energy-related data from U.S. commercial buildings (e.g., offices, hospitals, schools). Data include building characteristics (e.g., structure, operational characteristics) and energy use.
	U.S. EPA Analysis of Survey Data. Residential Energy Consumption Survey (RECS)	The Residential Energy Consumption Survey (RECS) collects energy-related data from U.S. households. Data include housing characteristics (e.g., floor space, lighting, electronics), energy consumption, and expenditures.
	U.S. EPA Field Sampling Procedures for Water Monitoring	EPA’s Region 9 has compiled a set of resources available on field sampling procedures for surface water monitoring.
	Uncertainty and Data Quality in Exposure Assessment Exit	This resource is split into two parts: Guidance on Characterizing and Communicating Uncertainty in Exposure Assessment and Hallmarks of Data Quality in Chemical Exposure Assessment. Topics covered include sources of uncertainty, tiered approach to uncertainty analysis, and communicating uncertainty. Several case studies are also provided.
	Understanding Contaminated Sediments: Bioavailability of Contamination Exit	Purdue University under an EPA grant issued a publication entitled Understanding Contaminated Sediments: Bioavailability of Contamination. This short publication discusses issues associated with bioavailability of contaminants in sediments.
	Understanding Variation in Partition Coefficients Kd values	This resource is a 3-volume report that describes the conceptualization, measurement, and use of the partition coefficient (Kd), which is a parameter used in chemical transport modeling.
	Updated Dermal Exposure Assessment Guidance	This memorandum represents updated EPA Region 3 guidance on conducting dermal risk assessment at Superfund sites. In general, Region 3 follows recommendations in RAGS Part E, but also offers some Region-specific recommendations.
	Urban Airshed Model Variable Grid Urban Airshed Model (UAM-V); 7th Conference information	The UAM-V Model is a three-dimensional, multi-scale photochemical grid model that calculates concentrations of pollutants by simulating the physical and chemical processes in the atmosphere.
	Use of Physiologically Based Pharmacokinetic (PBPK) Models to Quantify the Impact of Human Age and Interindividual Differences in Physiology and Biochemistry Pertinent to Risk (Final Report)	This report addresses the quantification, extrapolation, and interpretation of advanced biochemical information on human interindividual variability of chemical metabolism for risk assessment application. Topics covered by this resource include data quality, experimental framework, and required data. Two example case studies are also presented.
	User's Guide for the Integrated Exposure Uptake Model for Lead in Children (IEUBK)	This user's guide is a comprehensive reference for the IEUBK model, including installation, model inputs, analysis, and interpretation.
	User’s Guide for the Johnson and Ettinger (1991) Model for Subsurface Vapor Intrusion into Buildings	This resource provides guidance for the use of the Johnson and Ettinger Subsurface Vapor Intrusion Model.
	Vapor Intrusion website	This web site provides basic information on vapor intrusion for the general public, homeowners, community leaders, environmental professionals, and other interested parties. Also, included at this site are links to several documents and tools to support development of the Final Subsurface Vapor Intrusion Guidance, including: EPA Spreadsheet for Modeling Subsurface Vapor Intrusion; Vapor Intrusion Database; Background Indoor Air Concentrations of Volatile Organic Compounds in North American Residences (1990–2005): A Compilation of Statistics for Assessing Vapor Intrusion; Vapor Intrusion Screening Levels; Conceptual Model Scenarios for the Vapor Intrusion Pathway; and Indoor Air Vapor Intrusion Mitigation Approaches.
	Ventilation Rates in U.S. Office Buildings From the EPA Base Study	This resource provides information about a NIST study that collected indoor environmental measurements, including outdoor ventilation rates in 100 U.S. office buildings.
	Virtual Beach (VB) Model	Virtual Beach is a software package designed to construct site-specific Multiple Linear Regression (MLR) models for the prediction of pathogen indicator levels at recreational beaches.
	Virtual Tour of a Drinking Water Plant	The virtual tour provides step-by-step information on how water is treated and delivered to the community.
	Visual Plumes Model System	The Visual Plumes model system can be used for simulating surface water jets and plumes and assist with mixing zone analyses, Total Maximum Daily Loads (TMDLs), and other water quality applications.
	VOCs website	This website provides general information on VOC exposure and sources in homes and buildings.
	Volatile Organic Compounds (VOCs) on the Gulf Coastline	This website provides information on EPA’s efforts to sample and screen for VOCs in ambient air following the BP Oil Spill.
	Volatile Organic Compounds in Your Home Exit	This website describes the variety of VOCs that are commonly found in residential environments.
	Volatilization Rates from Water to Indoor Air Phase II	EPA developed mass balance models for estimating chemical emissions for 5 tracer chemicals (acetone, ethyl acetate, toluene, ethylbenzene, and cyclohexane) from 4 sources (showers, dishwashers, washing machines, and bathtubs) to better characterize chemical volatilization from drinking water to indoor air. These experiments led to the development of source- and chemical-specific mass transfer coefficients, air exchange (ventilation) rates, and chemical stripping efficiencies. EPA also describes a set of protocols for estimating emission rates for chemicals other than the 5 tracer chemicals examined for this study.
	Wabanaki Traditional Cultural Lifeways Exposure Scenario	This document presents an exposure scenario of the environmental contact, diet, and exposure pathways present in traditional cultural lifeways in Maine. These traditional uses are described as a single best representation of subsistence-traditional lifeways. This project report is intended to reflect the lifeways of people fully using natural resources and pursuing traditional cultural lifeways.
	Wadeable Streams Assessment (WSA)	The Wadeable Streams Assessment (WSA) is a collaborative effort among EPA, states, other federal agencies, tribes, universities and other organizations to monitor and analyze the biological condition of small streams.
	Wall Paint Exposure Assessment Model (WPEM)	WPEM is used to estimate the potential exposure of consumers and workers to the chemicals emitted from wall paint applied using a roller or a brush.
	Water Contaminant Information Tool	The water contamination tool is a limited access secured database that provides information on chemical, biological, and radiological contaminants. The tool is intended to be used by personnel from drinking water and wastewater utilities, state primacy agencies, federal officials, public health agencies, and water associations.
	Water Health Series: Filtration Facts	This resource contains information about home water treatment filtration options.
	Water Quality Analysis Simulation Program (WASP7)	Water Quality Analysis Simulation Program is a dynamic compartment-modeling program for aquatic systems to assist with the interpretation and prediction of water quality responses to natural phenomena and manmade pollution for various pollution management decisions.
	Water Resources website	This resource provides hydrologic and water-quality information collected by USGS and provides access to water data, publications, and maps, as well as to recent water projects and events.
	WATER9 Model	WATER9, a wastewater treatment model, estimates air emissions of individual waste constituents in wastewater collection, storage, treatment, and disposal facilities.
	Watershed Assessment, Tracking & Environmental ResultS (WATERS)	EPA's WATERS program unites water quality information that was previously available only from several independent and unconnected databases to help address public concerns regarding water quality and health.
	Watershed Health Assessment Tools Investigating Fisheries (WHATIF) Models	WHATIF is a software package that integrates a number of calculators, tools, and models for assessing the health of watersheds and streams focusing on fish communities in the Mid-Atlantic Highland region.
	Watershed Management Optimization Support Tool (WMOST)	WMOST is a tool for local water resources managers and planners to screen a wide-range of potential water resources management options across their watershed or jurisdiction. The tool is intended to aid in evaluating the environmental and economic costs, benefits, trade-offs and co-benefits of various management options. The model is spatially lumped with a daily or monthly time step and considers water flows but does not yet consider water quality. The optimization of management options is solved using linear programming. WMOST is maintained by EPA’s Center for Exposure Assessment Modeling (CEAM).
	Web Soil Survey (WSS)	The Web Soil Survey provides access to soil survey information including online data and soil maps for most U.S. counties.
	Wellhead Analytic Element Model (WhAEM2000)	The Wellhead Analytic Element Model (WhAEM2000) is a groundwater geohydrology computer program designed to facilitate capture zone delineation and protection area mapping.
	What We Eat in America	This website contains data tables, research articles and other documentation sources for food and nutrient intakes of Americans.
	Where You Live: Your Drinking Water Quality Reports Online	This website provides links to drinking water quality reports by state. Users can also find the contact information for specific water systems in their state.
	Who's Minding the Kids? Child Care Arrangements Data	The U.S. Census compiled the comprehensive report “Who's Minding the Kids? Childcare Arrangements” from data originating from the Survey of Income and Program Participation. Data tables for information on childcare use and the cost and receipt of government assistance relating to childcare are included. Data are reported for all children under the age of 15 (regardless of parental labor force status).
	Workplace Exposure to Nanoparticles Exit	This report provides information on occupational exposure to nanomaterials including health effects.
	Workplace Safety & Health: Indoor Environmental Quality	This NIOSH web site discusses issues related to indoor air quality for occupational populations. Links to various resources and related topics are provided.
	Workshop on Human and Environmental Exposure Assessment, workshop report	The report of the National Nanotechnology Initiative Workshop discusses the research needs related to exposure to nanomaterials. Research areas include characterizing exposure among workers and the general population, identifying population groups and environments that might be exposed to nanomaterials, and characterizing the health of exposed populations and environments.
	Workshop on Human and Environmental Exposure Assessment, workshop website	This website for the 2009 Human and Environmental Exposure Assessment Workshop addresses the National Nanotechnology Initiative’s Strategy for Nanotechnology-Related Environmental Health, and Safety Research. Links to the agenda, workshop presentations, and the official workshop report are available.
	Workshop on Nanomaterials and Human Health & Instrumentation, Metrology, and Analytical Methods, workshop report	The report of the National Nanotechnology Initiative Workshop discusses the research needs related to in vivo and in vitro characterization of nanomaterials as well as nano-informatics and data-enabled predictive modeling of nanomaterials.
	Workshop on Nanomaterials and Human Health & Instrumentation, Metrology, and Analytical Methods, workshop website	This website is for the third of a four-part series of workshops held between February 2009 and March 2010 which addresses the National Nanotechnology Initiative’s Strategy for Nanotechnology-Related Environmental Health, and Safety Research. Links to the agenda, workshop presentations, and the official workshop report are available.
	Workshop on Nanotechnology for Site Remediation	This report provides conference proceedings from the first conference in a series of environmental nanotechnology conferences held by EPA. It focuses on nanotechnology for site remediation and includes written summaries of discussion on NZVI, nano-porous materials, and nanoscale colloids.
	World FactBook: Life Expectancy at Birth	This website provides life expectancy information from various countries in the world.