Glossary
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Abatement: Reducing the degree or intensity of, or eliminating, pollution
Absorption: The process of taking in. For a person or an animal, absorption is the process of a substance getting into the body through the eyes, skin, stomach, intestines, or lungs. The uptake of water, other fluids, or dissolved chemicals by a cell or an organism (as tree roots absorb dissolved nutrients in soil.)
Absorption Barrier: Any of the exchange sites of the body that permit uptake of various substances at different rates (e.g. skin, lung tissue, and gastrointestinal-tract wall)
Accumulation : Build up of a chemical in a body due to long term exposure. The net accumulation of a contaminant in an organism from all sources, including air, water and food. Toxic chemicals tend to bioaccumulate in the fatty tissues of fish, and these toxins increase in concentration as they are passed from the prey to the predator (called biomagnification
Acute Exposure: A single exposure to a toxic substance which may result in severe biological harm or death. Acute exposures are usually characterized as lasting no longer than a day, as compared to longer, continuing exposure over a period of time. Contact with a substance that occurs once or for only a short time (up to 14 days) {compare with intermediate duration exposure and chronic exposure
Acute : Occurring over a short period of time
Acute Toxicity : Causing adverse effect that occur very rapidly after a single exposure has occurred. The ability of a substance to cause severe biological harm or death soon after a single exposure or dose. Also, any poisonous effect resulting from a single short-term exposure to a toxic substance. (See: chronic toxicity, toxicity.)
Additive Effect : Combined effect of two or more chemicals equal to the sum of their individual effects. A biologic response to exposure to multiple substances that equals the sum of responses of all the individual substances added together (compare with antagonistic effect and synergistic effect
Adsorption: Removal of a pollutant from air or water by collecting the pollutant on the surface of a solid material; e.g., an advanced method of treating waste in which activated carbon removes organic matter from waste-water.
Adverse health effect: A change in body function or cell structure that might lead to disease or health problems
Ambient: Surrounding
Applied Dose: In exposure assessment, the amount of a substance in contact with the primary absorption boundaries of an organism (e.g. skin, lung tissue, gastrointestinal track) and available for absorption
Association : A relationship between an exposure and a disease. The relationship does not of itself confirm that the exposure caused the disease.
Bias : A distortion of the facts caused by errors in selecting or classifying the subjects of a study.
Background level : An average or expected amount of a substance or radioactive material in a specific environment or typical amounts of substances that occur naturally in an environment
EPA 1. Naturally occurring--substances present in the environment in forms that have not been
by human activity 2. Anthropogenic--natural and man-made substances present in the environment as a result of human activities not specifically related to the CERCLA site
. The concentration of a substance in an environmental media (air, water, or soil) that occurs naturally or is not the result of human activities. 2. In exposure assessment the concentration of a substance in a defined control area, during a fixed period of time before, during, or after a data-gathering operation.
Bioaccumulants: Substances that increase in concentration in living organisms as they take in contaminated air, water, or food because the substances are very slowly metabolized or excreted
Bioavailabiliity: Degree of ability to be absorbed and ready to interact in organism metabolism.
Bioconcentration: The accumulation of a chemical in tissues of a fish or other organism to levels greater than in the surrounding medium.
Biodegradable: Capable of decomposing under natural co Biological Magnification: Refers to the process whereby certain substances such as pesticides or heavy metals move up the food chain, work their way into rivers or lakes, and are eaten by aquatic organisms such as fish, which in turn are eaten by large birds, animals or humans. The substances become concentrated in tissues or internal organs as they move up the chain. (See: bioaccumulants.)
Biological Oxygen Demand (BOD): An indirect measure of the concentration of biologically degradable material present in organic wastes. It usually reflects the amount of oxygen consumed in five days by biological processes breaking down organic waste.
Biomonitoring: 1. The use of living organisms to test the suitability of effluents for discharge into receiving waters and to test the quality of such waters downstream from the discharge. 2. Analysis of blood, urine, tissues, etc. to measure chemical exposure in humans.
Bioremediation: Use of living organisms to clean up oil spills or remove other pollutants from soil, water, or wastewater; use of organisms such as non-harmful insects to remove agricultural pests or counteract diseases of trees, plants, and garden soil.
Brownfields: Abandoned, idled, or under used industrial and commercial facilities/sites where expansion or redevelopment is complicated by real or perceived environmental contamination. They can be in urban, suburban, or rural areas. EPA's Brownfields initiative helps communities mitigate potential health risks and restore the economic viability of such areas or properties.
Cadmium (Cd): A heavy metal that accumulates in the environment.
Chemical Compound: A distinct and pure substance formed by the union or two or more elements in definite proportion by weight.
Chemical Element: A fundamental substance comprising one kind of atom; the simplest form of matter.
Chronic Effect: An adverse effect on a human or animal in which symptoms recur frequently or develop slowly over a long period of time.
Chronic Exposure: Multiple exposures occurring over an extended period of time or over a significant fraction of an animal's or human's lifetime (Usually seven years to a lifetime.)
Chronic Toxicity: The capacity of a substance to cause long-term poisonous health effects in humans, animals, fish, and other organisms. (See: acute toxicity.)
Chronic toxicity: Causing adverse effects that occur after repeated exposures over a long period of time
Cluster : A group of individuals living in a limited area and manifesting a particular disease.
Confidence interval : The margin of error calculated for a risk estimate. 95% confidence interval means that there is a 95% probability that the risk is no higher or lower than the range of values included in this interval.
Contaminant: Any physical, chemical, biological, or radiological substance or matter that has an adverse effect on air, water, or soil.
Contamination: Introduction into water, air, and soil of microorganisms, chemicals, toxic substances, wastes, or wastewater in a concentration that makes the medium unfit for its next intended use. Also applies to surfaces of objects, buildings, and various household and agricultural use products
DDT: The first chlorinated hydrocarbon insecticide chemical name: Dichloro-Diphenyl-Trichloroethane. It has a half-life of 15 years and can collect in fatty tissues of certain animals. EPA banned registration and interstate sale of DDT for virtually all but emergency uses in the United States in 1972 because of its persistence in the environment and accumulation in the food chain
Decomposition: The breakdown of matter by bacteria and fungi, changing the chemical makeup and physical appearance of materials.
Decontamination: Removal of harmful substances such as noxious chemicals, harmful bacteria or other organisms, or radioactive material from exposed individuals, rooms and furnishings in buildings, or the exterior environment.
Dermal Exposure: Contact between a chemical and the skin.
Dermal Toxicity: The ability of a pesticide or toxic chemical to poison people or animals by contact with the skin
Dosage/Dose: 1. The actual quantity of a chemical administered to an organism or to which it is exposed. 2. The amount of a substance that reaches a specific tissue (e.g. the liver). 3. The amount of a substance available for interaction with metabolic processes after crossing the outer boundary of an organism
Dose : A measure of exposure. Dose is often expressed in milligrams per kilogram.
Dose-Response Assessment: 1. Estimating the potency of a chemical. 2. In exposure assessment, the process of determining the relationship between the dose of a stressor and a specific biological response. 3. Evaluating the quantitative relationship between dose and toxicological responses
Dose-Response Relationship: The quantitative relationship between the amount of exposure to a substance and the extent of toxic injury or disease produced
Epidemiology : The study of patterns of disease in populations.
Environmental Exposure: Human exposure to pollutants originating from facility emissions. Threshold levels are not necessarily surpassed, but low-level chronic pollutant exposure is one of the most common forms of environmental exposure
Exposure: The amount of radiation or pollutant present in a given environment that represents a potential health threat to living organisms.
Exposure :1)The amount, frequency, and duration of contact with an environmental agent. 2) In epidemiology, anything that increases the likelihood of disease. You can be exposed to a substance only when you come in contact with it. You may be exposed by breathing, eating, or drinking substances containing the substance or by skin contact with it.
Exposure Assessment: Identifying the pathways by which toxicants may reach individuals, estimating how much of a chemical an individual is likely to be exposed to, and estimating the number likely to be exposed.
Exposure Assessment : A step in risk assessment that estimates how much of a substance people are actually exposed to.
Exposure Concentration: The concentration of a chemical or other pollutant representing a health threat in a given environment.
Exposure Indicator: A characteristic of the environment measured to provide evidence of the occurrence or magnitude of a response indicator's exposure to a chemical or biological stress.
Exposure Level: The amount (concentration) of a chemical at the absorptive surfaces of an organism.
Exposure Pathway: The path from sources of pollutants via, soil, water, or food to man and other species or settings.
Exposure Route: The way a chemical or pollutant enters an organism after contact; i.e. by ingestion, inhalation, or dermal absorption.
Exposure-Response Relationship: The relationship between exposure level and the incidence of adverse effects.
Extrapolate: Estimate or infer something by extending or projecting known information.
Fossil Fuel: Fuel derived from ancient organic remains; e.g. peat, coal, crude oil, and natural gas.
Fungus (Fungi): Molds, mildews, yeasts, mushrooms, and puffballs, a group of organisms lacking in chlorophyll (i.e. are not photosynthetic) and which are usually non-mobile, filamentous, and multicellular. Some grow in soil, others attach themselves to decaying trees and other plants whence they obtain nutrients. Some are pathogens, others stabilize sewage and digest composted waste.
Half-Life: 1. The time required for a pollutant to lose one-half of its original coconcentrationor example, the biochemical half-life of DDT in the environment is 15 years. 2. The time required for half of the atoms of a radioactive element to undergo self-transmutation or decay (half-life of radium is 1620 years). 3. The time required for the elimination of half a total dose from the body.
Hazard: 1. Potential for radiation, a chemical or other pollutant to cause human illness or injury. 2. In the pesticide program, the inherent toxicity of a compound. Hazard identification of a given substances is an informed judgment based on verifiable toxicity data from animal models or human studies.
Hazardous : The potential that the use of a product will result in an adverse effect on humans or the environment in a given situation. The degree of hazard is based on the substance’s characteristics, such as toxicicty, flammability, explosiveness, corrosiveness, etc. and the ease with which people or the environment can come in contact with it. Hazardous is not the same as toxicity. A general term to denote any substance that is either a physical hazard (an explosive) or a health hazard ( a poison) Toxic is a more specific term referring only to health hazard
Hazardous Substance: 1. Any material that poses a threat to human health and/or the environment. Typical hazardous substances are toxic, corrosive, ignitable, explosive, or chemically reactive. 2. Any substance designated by EPA to be reported if a designated quantity of the substance is spilled in the waters of the United States or is otherwise released into the environment.
Hazardous Waste: By-products of society that can pose a substantial or potential hazard to human health or the environment when improperly managed. Possesses at least one of four characteristics (ignitability, corrosivity, reactivity, or toxicity), or appears on special EPA lists.
Heavy Metals: Metallic elements with high atomic weights; (e.g. mercury, chromium, cadmium, arsenic, and lead); can damage living things at low concentrations and tend to accumulate in the food chain.
High End Exposure (dose) Estimate: An estimate of exposure, or dose level received anyone in a defined population that is greater than the 90th percentile of all individuals in that population, but less than the exposure at the highest percentile in that population. A high end risk descriptor is an estimate of the risk level for such individuals. Note that risk is based on a combination of exposure and susceptibility to the stressor.
High-Risk Community: A community located within the vicinity of numerous sites of facilities or other potential sources of envienvironmental exposure/health hazards which may result in high levels of exposure to contaminants or pollutants.
High-to-Low-Dose Extrapolation: The process of prediction of low exposure risk to humans and animals from the measured high-exposure-high-risk data involving laboratory animals.
Human Equivalent Dose: A dose which, when administered to humans, produces an effect equal to that produced by a dose in animals.
Joint and Several Liability: Under CERCLA, this legal concept relates to the liability for Superfund site cleanup and other costs on the part of more than one potentially responsible party (i.e. if there were several owners or users of a site that became contaminated over the years, they could all be considered potentially liable for cleaning up the site.)
Lowest Acceptable Daily Dose: The largest quantity of a chemical that will not cause a toxic effect, as determined by animal studies.
Lowest Observed Adverse Effect Level (LOAEL): The lowest level of a stressor that causes statistically and biologically significant differences in test samples as compared to other samples subjected to no stressor.
Mold : a fungus; molds are plants that make spores instead of seeds which float in the air like pollen. Molds, mushrooms, mildews, and yeasts are all classified as fungi, a kingdom of organisms, distinct from plants and animals. Molds are ubiquitous in nature and grow almost anywhere indoors or outdoors. Molds spread and reproduce by making spores, which are small and lightweight, able to travel through air, capable of resisting dry, adverse environmental conditions, and hence capable of surviving a long time.
Morbidity: Rate of disease incidence.
Mortality: Death rate
Mutagen/Mutagenicity: An agent that causes a permanent genetic change in a cell other than that which occurs during normal growth. Mutagenicity is the capacity of a chemical or physical agent to cause such permanent changes.
No Observable Adverse Effect Level (NOAEL): An exposure level at which there are no statistically or biologically significant increases in the frequency or severity of adverse effects between the exposed population and its appropriate control; some effects may be produced at this level, but they are not considered as adverse, or as precurors to adverse effects. In an experiment with several NOAELs, the regulatory focus is primarily on the highest one, leading to the common usage of the term NOAEL as the highest exposure without adverse effects
NOAEL (no observable adverse effect level) In a dose-response study, the highest dose at which no observable adverse effects occur
No-Observed-Effect-Level (NOEL): Exposure level at which there are no statistically or biological significant differences in the frequency or severity of any effect in the exposed or control populations.
Carcinogen: Any substance capable of producing or inducing cancer
NOEL (no observed effect level) In a dose-response study, the highest dose at which no observable effects occur
Particulates: 1. Fine liquid or solid particles such as dust, smoke, mist, fumes, or smog, found in air or emissions. 2. Very small solids suspended in water; they can vary in size, shape, density and electrical charge and can be gathered together by coagulation and flocculation
Permeability: The rate at which liquids pass through soil or other materials in a specified direction.
Permissible Dose: The dose of a chemical that may be received by an individual without the expectation of a significantly harmful result.
Permissible Exposure Limit : Also referred to as PEL, federal limits for workplace exposure to contaminants as established by OSHA.
Pesticide: Substances or mixture there of intended for preventing, destroying, repelling, or mitigating any pest. Also, any substance or mixture intended for use as a plant regulator, defoliant, or desiccant.
Petroleum: Crude oil or any fraction thereof that is liquid under normal conditions of temperature and pressure. The term includes petroleum-based substances comprising a complex blend of hydrocarbons derived from crude oil through the process of separation, conversion, upgrading, and finishing, such as motor fuel, jet oil, lubricants, petroleum solvents, and used oil.
Phytoremediation: Low-cost remediation option for sites with widely dispersed contamination at low concentrations.
Pollutant: Generally, any substance introduced into the environment that adversely affects the usefulness of a resource or the health of humans, animals, or ecosystems..
Pollutant Pathways: Avenues for distribution of pollutants. In most buildings, for example, HVAC systems are the primary pathways although all building components can interact to affect how air movement distributes pollutants.
Power : A study’s ability to find an effect, expressed as a percent from 0 to 100. The larger the sample size, the more likely it is that the study will find an effect, if one exists.
Remediation: 1. Cleanup or other methods used to remove or contain a toxic spill or hazardous materials from a Superfund site; 2. for the Asbestos Hazard Emergency Response program, abatement methods including evaluation, repair, enclosure, encapsulation, or removal of greater than 3 linear feet or square feet of asbestos-containing materials from a building.
Residue: The dry solids remaining after the evaporation of a sample of water or sludge.
Response Action: 1. Generic term for actions taken in response to actual or potential health-threatening environmental events such as spills, sudden releases, and asbestos abatement/management problems. 2. A CERCLA-authorized action involving either a short-term removal action or a long-term removal response. This may include but is not limited to: removing hazardous materials from a site to an EPA-approved hazardous waste facility for treatment, containment or treating the waste on-site, identifying and removing the sources of ground-water contamination and halting further migration of contaminants. 3. Any of the following actions taken in school buildings in response to AHERA to reduce the risk of exposure to asbestos: removal, encapsulation, enclosure, repair, and operations and maintenance. (See: cleanup.)
Responsiveness Summary: A summary of oral and/or written public comments received by EPA during a comment period on key EPA documents, and EPA's response to those comments.
Risk Assessment: Qualitative and quantitative evaluation of the risk posed to human health and/or the environment by the actual or potential presence and/or use of specific pollutants.
Risk Assessment : A scientific process that estimates the type and magnitude of risk to human health posed exposure to chemical substances.
Risk Characterization: The last phase of the risk assessment process that estimates the potential for adverse health or ecological effects to occur from exposure to a stressor and evaluates the uncertainty involved.
Risk Characterization : The final step in risk assessment. Combines information on toxicity and exposure to describe what the risk is likely to be.
Risk Factor: Characteristics (e.g., race, sex, age, obesity) or variables (e.g., smoking, occupational exposure level) associated with increased probability of a toxic effect.
Safe: Condition of exposure under which there is a practical certainty that no harm will result to exposed individuals
Tetratogen : A substance that can cause malformation in the fetus following exposure to the mother.
Threshold: The lowest dose of a chemical at which a specified measurable effect is observed and below which it is not observed.
Threshold: The dose or exposure level below which a significant adverse effect is not expected.
Toxicity: The inherent potential of a substance to cause systematic damage to living organisms