Glossary, Risk Commission Final Report, Vol. 2

acceptable daily intake (ADI)	A routine approach of FDA and other U.S. and international governmental and nongovernmental organizations to set safe levels of oral intake for chemicals by dividing the no-observed-adverse-effect-level (NOAEL) by safety and uncertainty factors of two to four values of 10 (100 to 10,000).
affected parties	Individuals and organizations acted upon by chemicals, radiation, or microbes in the environment or influenced favorably or adversely by proposed risk management actions and decisions.
alternative compliance	A policy which allows facilities to choose among methods for achieving emission-reduction or risk-reduction specifications instead of command-and-control regulations that specify standards and how to meet them. An example of alternative compliance is the use of a theoretical bubble over a facility to cap the amount of pollution emitted while allowing the company to choose where and how within the facility it gets to or stays below the cap.
antagonistic interactions	An adverse effect resulting from exposure to two or more chemicals that is less than that predicted by adding their independent effects together, often due to interference with each other’s action.
aquatic ecosystem	A water ecosystem, such as a stream, lake, or bay.
attainment area	A geographical area, such as a city, state, or regional airshed, that is meeting EPA clean air standards.
benchmark	A standard of evaluation.
benchmark dose	An exposure level that corresponds to a statistical lower bound on a standard probability of an effect, such as 10% of people affected.
benefit-cost analysis (BCA)	An economic method for assessing the benefits and costs of achieving alternative health-based standards with different levels of health protection.
bioassay	Evaluation of a chemical’s toxicity using laboratory animals or other test organisms.
biologic markers	Changes in the characteristics of a biologic sample, such as changes in enzyme levels or mutations in specimens such as blood cells, that reflect a particular environmental exposure, a particular human or animal disease process, or evidence of increased or decreased susceptibility to adverse effects from such exposures.
bright line	Specific levels of risk or of exposure that are meant to provide a practical distinction between what is considered safe and what is not.
brownfields	Idle, contaminated urban properties.
carcinogen	A cancer-causing agent.
central tendency	The mean (average) or the median ( midpoint) of a range of relevant risk estimates for a particular situation, exposure, or chemical hazard.
chronic health effects	Diseases occurring as a result of repeated or persistent exposures.
collaborative stakeholder involvement	Engaging interested and affected parties in the substantive work of risk management, through all 6 stages of the Commission’s Framework.
command-and-control regulations	Specific requirements prescribing how to comply with specific standards defining acceptable levels of pollution.
Common Sense Initiative	A current EPA initiative that convenes teams of stakeholders in six major industrial sectors—automobile manufacturing, computers and electronics, iron and steel, metal finishing, petroleum refining, and printing—to find comprehensive and feasible strategies to reduce pollution.
comparative risk analysis	The process of comparing and ranking various types of risks to identify priorities and influence resource allocations.
comparisons of risk	Using two or several more-or-less similar or equivalent risks to assist in communicating information about risk estimates.
contaminants	Chemicals, microorganisms, or radiation found in air, soil, water, or food that are not normally constituents of these environmental media or are found at increased concentrations due to human activities.
context	Here refers to public health and ecological assessment of the contribution of any particular environmental hazard to health, safety, or the environment.
cost-effectiveness analysis (CEA)	An economic method to identify the least costly way to achieve a particular health protection goal.
cumulative	Enlarging or increasing by successive addition.
cytotoxicity	Causing harm to a cell.
disease incidence	The prevalence of new occurrences of a disease.
disposition	The transport and fate of chemicals, microbes, or other agents in the environment and inside living organisms, including humans.
dose-response relationship	The relationship between exposure level and the incidence of adverse effects.
ecological risk assessment	A process used to estimate the likelihood of adverse effects on plants and/or animals from exposure to stressors, such as chemicals or draining of wetlands. The process includes problem formulation, characterization of exposure, characterization of ecological effects, and risk characterization.
economic analysis	Used here to refer to an analysis in monetary values of the costs and benefits of various actions to protect health or the environment.
end-of-the-pipe	Relying on technologies, such as scrubbers on smokestacks and catalytic converters on vehicle tailpipes, to reduce emissions of pollutants after they have formed.
environmental accounting	Incorporating all costs involved in design, production, use, disposal, and reuse of resources contrasted with traditional methods of accounting in which energy costs are assigned to overhead, and effects on and uses of air, water, and soil are ignored.
environmental audits	An examination of records or accounts relating to corporate or public sector activities that may adversely affect or protect the environment.
environmental indicators	Measures reflecting the health of the environment locally, nationally, or internationally.
environmental justice	Concern about the disproportionate occurrence of pollution and potential pollution-related health effects affecting low-income, cultural, and ethnic populations and lesser cleanup efforts in their communities.
epidemiology	The core public health science, investigating the causes and risk factors of disease and injury in populations and the potential to reduce such disease burdens.
equity	Just, fair, and impartial treatment of all people and population groups, including low-income, cultural, and ethnic populations potentially more affected by pollution.
exposure assessment	Determination of the sources, environmental transport and modification, and fate of pollutants and contaminants, including the conditions under which people or other target species could be exposed and the doses that could result.
exposure descriptors	Characteristic parameters measured, estimated, or assumed in assessing how much a population is exposed to contaminants. Breathing rate, daily food consumption, and contaminant concentrations in environmental media are examples.
exposure pathway	The path from sources of pollutants via air, soil, water, or food to reach people and other potentially affected species or settings.
extrapolation	Making inferences about the unknown by projecting or extending known information, using models and assumptions.
gavage	Introduction of material into the stomach via a tube through the mouth.
genotoxic	Capable of altering the structure of DNA and causing mutations.
hazard	A source of possible damage or injury.
high-end exposure estimate (HEEE)	Exposure levels at the higher end of a range of actual or estimated individual exposures, such as the 90th percentile level.
hyperplasia	A nontumorous increase in the number of cells in an organ or tissue with consequent enlargement of the affected part; sometimes a precursor to tumor formation.
industrial ecology	The analysis of an industrial system in which all materials, energy, and wastes are accounted for. An ideal system would reuse all materials, release no wastes, and minimize energy requirements.
interdependence	Mutual dependence.
interlocutory appeals	Legally challenging a regulatory rulemaking before that rulemaking is final.
international harmonization	Agreement across nations, as for toxicity testing protocols, clinical trials of pharmaceuticals, and even risk reduction requirements.
iterative process	Replication of a series of actions to produce successively better results, or to accommodate new and different critical information or scientific inferences.
judicial review	Acceptance by the courts of litigation challenging statutes and regulatory actions or proposals; the judicial branch check on legislative and executive branch actions.
life-cycle analysis	Tracking a product through all stages of its development, from extraction of fuel for power to production, use, and disposal.
lognormal	A logarithmic function with a normal distribution.
lower (and upper) confidence interval	Statistical parameters for a dose or a risk estimate indicating likely range of values, typically 95% range.
lowest effective dose (LED)	The lowest dose of a chemical that produced a specified level of an adverse effect when it was administered to animals in a toxicity study. For example, the LED₁₀ is the lowest effective dose that produced an effect in 10% of the exposed animals.
margin of exposure	A ratio defined by EPA as a dose derived from a tumor bioassay, epidemiologic study, or biologic marker study, such as the dose associated with a 10% response rate, divided by an actual or projected human exposure.
margin of protection	A ratio of the estimated risks associated with two doses, such as the risk associated with a no-observed-adverse effect level compared to the risk associated with an estimated human exposure level.
maximally exposed individual	A hypothetical person whose exposure to a contaminated medium is assumed to occur at the highest levels possible throughout his or her entire lifetime.
maximum-available-control technology (MACT)	The emission standard for sources of air pollution requiring the maximum degreeof reduction of hazardous air pollutants, taking cost and feasibility into account. Under section 112 of the Clean Air Act Amendments of 1990, the MACT must not be less than the average emission level achieved by controls on the best performing 12% of existing sources, by category of industrial and utility sources.
maximum tolerated dose (MTD)	The highest dose that can be administered to animals for two years without causing more than 10% loss of weight greater than controls or other evidence of significant systemic toxicity; the aim is to test chemicals at the highest dose feasible in laboratory animals, generally rats and mice.
measures of dispersion	The degree to which a characteristic, such as exposure level or benefits, is distributed across a population.
mechanisms of action	The sequence of a biologic process; the details of the process by which a chemical or other agent induces an adverse effect.
mechanistic data	Information about a chemical or other agent’s mechanisms of action and about similarities and differences between rodents and humans, for example.
mitigate	To make an impact less severe.
mobile sources	Vehicular sources of air pollution, such as cars, trucks, buses, planes, boats, and motorcycles.
mode of action	The way in which a chemical elicits toxicity; does not complete characterization of the mechanisms of action.
multimedia approach	A process for considering several environmental media, such as air, water, and land, together, rather than in isolation.
multiple risks	Risks from several sources or many agents.
noncarcinogen	An agent causing effects other than cancer, such as neurological, reproductive, or pulmonary effects.
nongenotoxic carcinogen	Cancer-causing agents which act without altering the structure of DNA.
nonpoint-source pollution	Diffuse sources of water pollution, such as runoff from streets, farms, and mines.
no-observed-adverse-effect level (NOAEL)	The highest dose of a chemical that was administered to animals in a toxicity study without producing an observed adverse effect.
options	Choices of actions.
peer review	Evaluation of the accuracy or validity of technical data, observations, and interpretation by qualified experts in an organized group process.
pharmacokinetics	Study of the absorption, distribution, metabolism, and excretion of chemicals and the genetic, nutritional, behavioral, and environmental factors that modify these parameters.
point source	In the Clean Water Act, pollution from a discharge pipe.
precautionary principle	Decisions about the best ways to manage or reduce risks that reflect a preference for avoiding unnecessary health risks instead of unnecessary economic expenditures when information about potential risks is incomplete.
probabilistic approaches	Evaluating a range of possible risk estimates and their likelihood, tied to various mathematical models of the likely distribution of potential values, instead of relying on single numbers or point estimates.
Project XL	An EPA initiative to give (as of 1996) six companies (Intel, Anheuser Busch, HADCO, Merck, AT&T Microelectronics, and 3M) and two government agencies (California’s South Coast Air Quality Management District and the Minnesota Pollution Control Agency) the flexibility to develop comprehensive strategies as alternatives to multiple current regulatory requirements to exceed compliance and increase overall environmental benefits.
public health context	The incidence, prevalence, and severity of diseases in communities and populations and the factors that account for such problems and that can be reduced or prevented; includes smoking, alcohol, diet, motor vehicle accidents, infections, chemical exposures, and other common voluntary and involuntary exposures or activities.
public health approach	A public health approach to risk management focuses on effective and feasible actions at the community level to reduce exposures and risks, with priority given to exposures with greatest impact (number of people and severity of effect).
record of decision	The cleanup actions agreed to by the principal responsible parties at a Superfund site.
reference concentration (RfC)	A concentration specified by EPA to limit human inhalation exposure to potentially hazardous levels of chemicals in air.
reference dose (RfD)	A dose specified by EPA to limit human oral exposure to potentially hazardous levels of chemicals that are thought to have thresholds for their effects (i.e., noncarcinogens).
residual risk	The health risk remaining after risk reduction actions are implemented, such as risks associated with sources of air pollution that remain after the implementation of maximum achievable control technology.
risk	The probability of a specific outcome, generally adverse, given a particular set of conditions.
risk assessment	An organized process used to describe and estimate the likelihood of adverse health outcomes from environmental exposures to chemicals. The four steps are hazard identification, dose-response assessment, exposure assessment, and risk characterization.
risk characterization	The process of organizing, evaluating, and communicating information about the nature, strength of evidence, and the likelihood of adverse health or ecological effects from particular exposures.
risk management	The process of analyzing, selecting, implementing, and evaluating actions to reduce risk.
salient	Prominent, having meaning to individuals or groups.
scoping	Defining the range of possibilities.
screening risk assessment	A risk assessment performed using few data and many assumptions to identify exposures that should be evaluated more carefully for their potential risks.
stationary sources	Fixed sources of air pollution, such as smokestacks and vents, contrasted with mobile (vehicular) sources.
susceptible populations	Populations which may exhibit a greater effect in response to particular exposures; generally, specific to the exposures or the effect.
sustainable development	Meeting the needs of the present without compromising the ability of future generations to meet their own needs; finding a convergence of environmental and economic goals.
synergistic interaction	An adverse effect resulting from exposure to two or more chemicals that is greater than the effect predicted by adding the effects of each.
threshold	The level of exposure above which adverse health effect is thought to occur, and below which no adverse effect is thought to occur.
tiered approach	A series of assessments of increasing complexity.
toxicity	The adverse effects of chemicals on living organisms.
transparency	Readily understandable, clear, not hidden.
tumorigenesis	Formation of tumors.
uncertainty analysis	Analysis of information about risks that is only partly known or unknowable. Mathematical uncertainty analyses can be used to generate probabilistic distributions of risk estimates that reflect the extent to which the information used to assess risk is uncertain.
variability	A population’s natural heterogeneity or diversity, particularly that which contributes to differences in exposure levels or in susceptibility to the effects of chemical exposures.
value of information	Value-of-information techniques provide an analytic framework for deciding whether it is better to make a decision now based on an inherently uncertain risk assessment or to collect additional information first and then decide.
weight of the scientific evidence	Considerations involved in assessing the interpretation of published scientific information—quality of methods, ability of a study to detect adverse effects, consistency of results across studies, and biological plausibility of cause-and-effect relationships.