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Development of Personal Ozone Samplers: Three Approaches
EPA Grant Number: R828112C063Subproject: this is subproject number 063 , established and managed by the Center Director under grant R828112
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
Center: Health Effects Institute
Center Director: Greenbaum, Daniel S.
Title: Development of Personal Ozone Samplers: Three Approaches
Investigators: Hackney, Jack D. , Anderson, Karen R. , Avol, Edward L. , Bunyaviroch, Arnold , Froelich, Susan , Koutrakis, Petros , Linn, William S. , Wolfson, Jack M. , Yanagisawa, Yukio
Institution: Rancho Los Amigos Medical Center , Harvard School of Public Health
Current Institution: Harvard School of Public Health
EPA Project Officer: Katz, Stacey
Project Period:
RFA: Health Effects Institute (1996)
Research Category: Ozone , Public/Private Partnership Center
Description:
Objective:Ozone is formed in the lower atmosphere when emissions from mobile and industrial sources react in the presence of sunlight. Because ozone is a highly reactive gas and a major component of urban smog, the Environmental Protection Agency has set a standard for ozone of 120 parts per billion for one hour, a level not to be exceeded more than once per year. Ozone is a major public health concern because exercising subjects experience transient decrements in lung function when exposed to ambient air containing ozone at concentrations equal to, or slightly below, the level of the current standard. In addition, because indoor ozone concentrations can exceed 50% of outdoor concentrations, people may be exposed to ozone for several hours each day. Assessing the risk of adverse health effects from such exposures is difficult because only limited data are available on the actual ozone concentrations that people experience.
Fixed-site monitors, which measure ambient ozone levels over widely spaced areas, are large and expensive to operate. Thus, these monitors cannot be used to measure individual exposures of large numbers of human subjects; in addition, their readings may not accurately reflect ozone levels in different microenvironments. In contrast, small personal ozone samplers measure total accumulated exposure as a person moves from one setting to another. Thus, personal samplers can improve the estimate of the exposure that an individual experiences and can provide better information for assessing the risk of exposure to ozone.
The Health Effects Institute supported three studies to advance the development and testing of personal ozone samplers. The results of these studies are discussed breifly here.
Approach:The investigators funded under the HEI ozone sampler program, Drs. Hackney, Yanagisawa, and Koutrakis, and their collaborators used different approaches to develop personal ozone samples that would be sensitive, accurate, and amenable to use in epidemiological studies.
Dr. Hackney and colleagues designed active and passive samplers based on ozone-induced changes in the intensity of a color formed by a chemical reagent. (Passive samplers depend on the natural diffusion of air and gases to the collection site, and active samplers use a pump to draw air into the device.) Dr. Hackney and associates coated filter papers with a reagent that forms a pink color after ozone exposure. By extracting the reaction product from the paper and measuring the intensity of the colored solution, they determined the amount of ozone that had reacted with the reagent. The investigators also designed a light-tight sample holder to mitigate the reagent's sensitivity to light. When tested in an indoor exposure chamber using mixtures of filtered air and pure ozone, the samplers detected ozone relatively accurately at several combinations of temperature and humidity. The active sampler was less accurate at lower humidity than at higher humidity, and the passive sampler's performance declined when it was tested at a combination of high temperature and high humidity. Both active and passive samplers performed less satisfactorily outdoors than indoors. The active device was accurate only for one- to two-hour exposures; the passive device overestimated ozone levels. Based on these results, the investigators concluded that the slower process of air diffusion, inherent in the passive design, allowed an unknown interfering component of ambient air to contact the reagent for a longer time than in the active sampler. For these reasons, the samplers based on the reagent used by Dr. Hackney and colleagues were not considered for further development. Although the reagent appeared promising in early laboratory tests, the investigators' careful experimental work indicated that it was problematic in a practical application.
Dr. Yanagisawa's passive sampler is based on ozone oxidizing iodide ion to molecular iodine. The unique feature of this sampler is that as the reaction proceeds on a carbon disk coated with a nylon derivative and potassium iodide, the volatile iodine product stabilizes by forming an electrically charged complex with nylon. The amount of current discharged by the complex then is a measure of the amount of iodine bound to nylon, and thus, the amount of ozone that had reacted with iodide ion to form molecular iodine. In chamber studies, the amount of charged complex formed increased with increasing ozone exposure levels. The sampler was generally unaffected by wind, temperature, or relative humidity, except at very low humidity levels (12%). Sulfur dioxide decreased iodine formation by ozone, but this interference was eliminated by adding a filter to absorb the sulfur dioxide. However, nitrogen dioxide also was detected, thus interfering with ozone detection. Therefore, Dr. Yanagisawa's sampler must be considered a total oxidant sampler, rather than an ozone-specific sampler.
The third study evaluated the performance of a passive sampler previously designed by Dr. Koutrakis and colleagues. The sampler is based on ozone oxidizing nitrite ion, which is coated onto glass fiber filters, to nitrate ion. After extracting the ions from the filters with water, the investigators separated the nitrate ion from the nitrite ion by a process called ion chromatography. Although it requires a certain technical expertise, this method is efficient and rapid, both positive features when multiple samples from large epidemiological studies must be analyzed. In both indoor chamber experiments and outdoor field tests, good agreement was found between the ozone levels detected by Dr. Koutrakis' sampler and a reference ozone monitor; however, these comparisons need to be made systematically over a wider range of ozone levels than was done in this study. Initial chamber experiments indicated that the sampler was affected by wind velocity. However, wind velocity effects were adequately minimized by the use of a plastic wind shield. The investigators themselves did not perform interference studies as part of their HEI project. Results from another laboratory indicate that nitrogen dioxide, sulfur dioxide, and peroxyacetylnitrate do not interfere significantly with the sampler's performance. The sampler's performance also was not affected by temperature or relative humidity. A major uncertainty that needs to be addressed before the sampler is used in field studies is the method the investigators used to assess the sampler's accuracy. (A similar concern is also relevant to the accuracy of the other samplers discussed in this Research Report.) Sampling rates were determined by an equation that used concentrations derived from a standard reference ozone monitor, and the calculated ozone levels were compared with those obtained with the reference monitor to assess accuracy. Using sampling rate data that are independent of a standard monitor would be a more scientifically rigorous method to estimate an experimental sampler's accuracy. An independent validation of Dr. Koutrakis' sampler would allow researchers to determine if its performance is adequate to meet the objectives of a proposed study.
Supplemental Keywords:Air, ambient air quality, air toxics, epidemiology, health effects, particulate matter, human health risk assessment, mobile sources, air monitoring, ozone, human exposure, indoor air quality. , Air, Scientific Discipline, Health, RFA, indoor air, Risk Assessments, Health Risk Assessment, air toxics, Biochemistry, particulate matter, Environmental Chemistry, mobile sources, exposure and effects, ambient air quality, indoor air quality, inhalation, inhalation toxicology, air quality, ambient air, carcinogens, ozone, environmental health effects, automobiles, emissions, human health risk, lung inflammation, lung injury, air pollutants, engines, human health effects, particulates, motor vehicles, ambient particle health effects, ozone samplers, ozone monitoring, air pollution, inhalability, inhaled, lung, epithelial cells, human health, human exposure, PM, animal model
Progress and Final Reports:
Final Report
Main Center Abstract and Reports:
R828112 Health Effects Institute
Subprojects under this Center:
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
R828112C042 Does Inhalation of Methanol Vapor Affect Human Neurobehavior?
R828112C043 Human Responses to Nitrogen Dioxide
R828112C044 The Role of Inflammation in Ozone-Induced Lung Injury
R828112C045 How Does Exercise Affect the Dose of Inhaled Air Pollutants?
R828112C046 How Do Chemicals in Diesel Engine Exhaust Damage DNA?
R828112C047 Effect of Nitrogen Dioxide on Bacterial Respiratory infection
in Mice
R828112C048 Effects of Ozone Exposure on Airway Epithelium
R828112C049 Inhalation of Aldehydes and Effects on Breathing
R828112C050 Does Ozone Cause Precancerous Changes in Cells?
R828112C051 Effects of Formaldehyde on Human Airway Epithelial Cells Exposed in a Novel Culture System
R828112C052 Carbon Monoxide and Cardiac Arrhythmias
R828112C053 Effects of Formaldehyde and Particle-Bound Formaldehyde on Lung Macrophage Functions
R828112C054 Mechanisms for Protecting Lung Epithelial Cells Against Oxidant Injury
R828112C055 Relationship of Nitropyrene-Derived DNA Adducts to Carcinogenesis
R828112C056 Particle Trap Effects on Heavy-Duty Diesel Engine Emissions
R828112C057 Carbon Monoxide and Atherosclerosis
R828112C058 Nitrogen Dioxide and Respiratory Illness in Children
R828112C059 Noninvasive Methods for Measuring Ventilation in Mobile Subjects
R828112C060 Oxidant Air Pollutants and Lung Cancer: An Animal Model
R828112C061 Detection of Carcinogen-DNA Adducts: Development of New Methods
R828112C062 Effects of Carbon Monoxide on Heart Muscle Cells
R828112C063 Development of Personal Ozone Samplers: Three Approaches
R828112C064 Development of Biomarkers to Monitor Carcinogen Exposure
R828112C065 Effects of Prolonged Ozone Inhalation on Collagen Structure and Content in Rat Lungs
R828112C065II Prolonged Ozone Exposure and the Contractile Properties of Isolated Rat Airways
R828112C065III Changes in Complex Carbohydrate Content and Structure in Rat Lungs Caused by Prolonged Ozone Inhalation
R828112C065IV Genetic Control of Connective Tissue Protein Synthesis After Prolonged Ozone Inhalation
R828112C065V Pulmonary Function Alterations in Rats After Chronic Ozone Inhalation
R828112C065VII Prolonged Ozone Exposure Leads to Functional and Structural Changes in the Rat Nose
R828112C065VIII - IX Studies of Changes in Lung Structure and Enzyme Activities
in Rats After Prolonged Exposure to Ozone
R828112C065X An Innovative Approach to Analyzing Multiple Experimental Outcomes: A Case Study of Rats Exposed to Ozone
R828112C065XI The Consequences of Prolonged Inhalation of Ozone on Rats:
An Integrative Summary of the Results of Eight Collaborative Studies
R828112C066 Interactive Effects of Nitropyrenes in Diesel Exhaust
R828112C067 Detection of Formaldehyde–DNA Adducts: Development of New Methods
R828112C068I Comparison of the Carcinogenicity of Diesel Exhaust and Carbon Black in Rat Lungs
R828112C068II An Investigation of DNA Damage in the Lungs of Rats Exposed to Diesel Exhaust
R828112C068III No Evidence For Genetic Mutations Found In Lung Tumors From Rats Exposed To Diesel Exhaust or Carbon Black
R828112C069 Noninvasive Determination of Respiratory Ozone Absorption: The Bolus-Response Method
R828112C070 The Effects of Inhaled Oxidants and Acid Aerosols on Pulmonary Function
R828112C071 Biochemical Consequences of Ozone Reacting with Membrane Fatty Acids
R828112C072 DNA Mutations in Rats Treated with a Carcinogen Present in Diesel Exhaust
R828112C073 Developmental Neurotoxicity of Inhaled Methanol in Rats
R828112C074 Methanol Distribution in Non Pregnant and Pregnant Rodents
R828112C075 Is Increased Mortality Associated with Ozone Exposure in Mexico City?
R828112C076 Effects of Fuel Modification and Emission Control Devices on Heavy-Duty Diesel Engine Emissions
R828112C077 Metabolic Studies in Monkeys Exposed to Methanol Vapors
R828112C078 Effects of Ozone on Pulmonary Function and Airway Inflammation in Normal and Potentially Sensitive Human Subjects
R828112C079 Improvement of a Respiratory Ozone Analyzer
R828112C080 Mechanism of Oxidative Stress from Low Levels of Carbon Monoxide
R828112C081 Long-Term Exposure to Ozone: Development of Methods to Estimate Past Exposures and Health Outcomes
R828112C082 Effects of Ambient Ozone on Healthy, Wheezy, and Asthmatic Children
R828112C083 Daily Changes in Oxygen Saturation and Pulse Rate Associated with Particulate Air Pollution and Barometric Pressure
R828112C084 Evaluation of The Potential Health Effects of the Atmospheric Reaction Products of Polycyclic Aromatic Hydrocarbons
R828112C085 Mechanisms of Response to Ozone Exposure: The Role of Mast Cells in Mice
R828112C086 Statistical Methods for Epidemiologic Studies of the Health Effects of Air Pollution
R828112C087 Development of New Methods to Measure Benzene Biomarkers
R828112C088 Alveolar Changes in Rat Lungs After Long-Term Exposure to Nitric Oxide
R828112C089 Effects of Prenatal Exposure to Inhaled Methanol on Nonhuman Primates and Their Infant Offspring
R828112C090 A Pilot Study of Potential Biomarkers of Ozone Exposure
R828112C091 Effects of Concentrated Ambient Particles on the Cardiac and Pulmonary Systems of Dogs
R828112C092 Cancer, Mutations, and Adducts in Rats and Mice Exposed to Butadiene and Its Metabolites
R828112C093 Effects of Concentrated Ambient Particles in Rats and Hamsters: An Exploratory Study
R828112C094I The National Morbidity, Mortality, and Air Pollution Study: Methods and Methodologic Issues
R828112C094II The National Morbidity, Mortality, and Air Pollution Study: Morbidity and Mortality from Air Pollution in the United States
R828112C095 Association of Particulate Matter Components with Daily Mortality and Morbidity in Urban Populations
R828112C096 Acute Pulmonary Effects of Ultrafine Particles in Rats and Mice
R828112C097 Identifying Subgroups of the General Population That May Be Susceptible to Short-Term Increases in Particulate Air Pollution
R828112C098 Daily Mortality and Fine and Ultrafine Particles in Erfurt, Germany
R828112C099 A Case-Crossover Analysis of Fine Particulate Matter Air Pollution and Out-of-Hospital Sudden Cardiac Arrest
R828112C100 Effects of Mexico City Air on Rat Nose
R828112C101 Penetration of Lung Lining and Clearance of Particles Containing Benzo[a]pyrene
R828112C102 Metabolism of Ether Oxygenates Added to Gasoline
R828112C103 Characterization and Mechanisms of Chromosomal Alterations Induced by Benzene in Mice and Humans
R828112C104 Acute Cardiovascular Effects in Rats from Exposure to Urban Ambient Particles
R828112C105 Genetic Differences in Induction of Acute Lung Injury and Inflammation in Mice
R828112C106 Effects on Mice of Exposure to Ozone and Ambient Particle Pollution
R828112C107 Emissions from Diesel and Gasoline Engines Measured in Highway Tunnels