Louisiana Department of Health and Hospitals/Office of Public Health
Under a Cooperative Agreement with the
Agency for Toxic Substances and Disease Registry
Louisiana Department of Environmental Quality, Hazardous Waste
Division
CERCLA
The Comprehensive Environmental Response, Compensation, and
Liability Act of 1980, also known as Superfund. This is the legislation
that mandates ATSDR public health assessment activities.
START
Superfund Technical Assessment and Response Team
CRI
Cameron Resources, Inc.
LDEQ-IASD
Louisiana Department of Environmental Quality, Inactive and
Abandoned Sites Division.
PVC
polyvinyl chloride
LDNR
Louisiana Department of Natural Resources
TDL
Target detection limit
SVOCs
Semivolatile organic compounds
RfD
Reference Dose
EMEG
Environmental Media Evaluation Guides
MRL
Minimal Risk Level
TCL
Target Compound List
BTEX
Benzene, toluene, ethylbenzene, and xylene.
PAHs
Polycyclic Aromatic Hydrocarbons
PCBs
Polychlorinated Biphenyls
CV
Comparison Values
BHC
beta hexachlorocyclohexene
LDOTD
Louisiana Department of Transportation and Development
bgs
below groundwater surface
mg/kg
Milligrams per kilogram
DEFINITIONS OF SELECTED TERMS
Background Level:
A typical or average level of a chemical in the environment. Background often refers to naturally occurring or uncontaminated levels.
Cancer Risk Evaluation Guides (CREGs):
CREGs are estimated contaminant concentrations that would be expected to cause no more than one excess cancer in a million (10-6) persons exposed over their lifetime. ATSDR's CREGs are calculated from U.S. EPA's cancer potency factors (CPFs).
Carcinogen:
A substance that has the potential to cause cancer.
Comparison Values:
Estimated contaminant concentrations in specific media that are not likely to cause adverse health effects, given a standard daily ingestion rate and standard body weight. The comparison values are calculated from the scientific literature available on exposure and health effects.
Concentration:
The amount of one substance dissolved or contained in a given amount of another. For example, sea water contains a higher concentration of salt than fresh water.
Contaminant:
Any substance or material that enters a system (the environment, human body, food, etc.) where it is not normally found.
Dermal:
Referring to the skin. Dermal absorption means absorption through the skin.
Dose:
The amount of a substance to which a person is exposed. Dose often takes body weight into account.
Environmental Contamination:
The presence of hazardous substances in the environment. From the public health perspective, environmental contamination is addressed when it potentially affects the health and quality of life of people living and working near the contamination.
Environmental Media Evaluation Guides (EMEGs) :
EMEGs are based on ATSDR minimal risk levels (MRLs) that consider body weight and ingestion rates. An EMEG is an estimate of daily human exposure to a chemical (in mg/kg/day) that is likely to be without noncarcinogenic health effects over a specified duration of exposure to include acute, intermediate, and chronic exposures.
Exposure:
Contact with a chemical by swallowing, by breathing, or by direct contact (such as through the skin or eyes). Exposure may be short term (acute) or long term (chronic).
Health Consultation:
A response to a specific question or request for information pertaining to a hazardous substance or facility (which includes waste sites). It often contains a time-critical element that necessitates a rapid response; therefore, it is a more limited response than an assessment.
Ingestion:
Swallowing (such as eating or drinking). Chemicals can get in or on food, drink, utensils, cigarettes, or hands where they can be ingested. After ingestion, chemicals can be absorbed into the blood and distributed throughout the body.
Inhalation:
Breathing. Exposure may occur from inhaling contaminants because they can be deposited in the lungs and absorbed into the blood.
mg/kg:
Milligrams per kilogram (a measure of concentration in soil or tissue, 1 mg/kg is equal to 1 part per million and 1000µg).
Media:
Soil, water, air, plants, animals, or any other parts of the environment that can contain contaminants.
Maximum Contaminant Level (MCL):
The MCL is the drinking water standard established by U.S. EPA. It is the maximum permissible level of a contaminant in water that is delivered to the free-flowing outlet. MCLs are considered protective of public health over a lifetime (70 years) for individuals consuming 2 liters of water per day.
Minimal Risk Level (MRL):
An MRL is defined as an estimate of daily human exposure to a substance that is likely to be without an appreciable risk of adverse effects (noncancer) over a specified duration of exposure. MRLs are derived when reliable and sufficient data exist to identify the target organ(s) of effect or the most sensitive health effect(s) for a specific duration via a given route of exposure. MRLs are based on noncancer health effects only. MRLs can be derived for acute, intermediate, and chronic duration exposures by the inhalation and oral routes.
No Apparent Public Health Hazard:
This public health conclusion category is used for sites where human exposure to contaminated media may be occurring, may have occurred in the past, and/or may occur in the future, but the exposure is not expected to cause any adverse health effects.
National Priorities List (NPL):
The U.S. Environmental Protection Agency's (U.S. EPA) listing of sites that have undergone preliminary assessment and site inspection to determine which locations pose immediate threats to persons living or working near the release. These sites are most in need of cleanup.
Potentially Exposed:
The condition where valid information, usually analytical environmental data, indicates the presence of contaminant(s) of a public health concern in one or more environmental media contacting humans (i.e., air, drinking water, soil, food chain, surface water), and there is evidence that some of those persons have an identified route(s) of exposure (i.e., drinking contaminated water, breathing contaminated air, having contact with contaminated soil, or eating contaminated food).
Parts per billion (ppb)/ Parts per million (ppm) :
Units commonly used to express low concentrations of contaminants. As example of each, one part per billion (ppb) of trichloroethylene (TCE) equals one drop of TCE mixed in a competition-size swimming pool and one part per million (ppm) equals one ounce of trichloroethylene (TCE) in one million ounces of water.
Public Health Assessment:
The evaluation of data and information on the release of hazardous substances into the environment in order to assess any current or future impact on public health, develop health advisories or other recommendations, and identify studies or actions needed to evaluate and mitigate or prevent human health effects; also, the document resulting from that evaluation.
Public Health Hazard:
This public health conclusion category is used for sites that pose a public health hazard due to the existence of long-term exposures to hazardous substances or conditions that could result in adverse health effects.
Reference Dose:
The value used by U.S. EPA as an estimate of daily exposure (mg/kg/day) to the general human population (including sensitive populations) that is likely to be without appreciable risk of harmful effects during a lifetime of exposure.
Reference Dose Media Evaluation Guides (RMEGs):
ATSDR derives RMEGs from U.S. EPA's oral reference doses. The RMEG represents the
concentration in water or soil at which daily human exposure is unlikely to result in adverse noncarcinogenic effects.
Risk:
In risk assessment, the probability that something will cause injury, combined with the potential severity of that injury.
Route of Exposure:
The way in which a person may contact a chemical substance. For example, drinking (ingestion) and bathing (skin contact) are two different routes of exposure to contaminants that may be found in water.
Superfund:
Another name for the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA), which created ATSDR.
Volatile Organic Compounds (VOCs):
Substances containing carbon and different proportions of other elements such as hydrogen, oxygen, fluorine, chlorine, bromine, sulfur, or nitrogen; these substances easily become vapors or gases. A significant number of the VOCs are commonly used as solvents (paint thinners, lacquer thinners, degreasers, and dry cleaning fluids).
