Early Action: An action which is taken when a hazardous waste site may become a threat to humans or the environment in the near future. Early Actions take anywhere from a few days to a few years and can be taken at any point in the Superfund process. Some sites can be completely cleaned up through a removal action and other sites may require long-term action. Early Actions may include: 1) cleanup or removal of substances threatening to contaminate the environment; 2) installation of security fences to limit access to the site; 3) provision of alternative water supplies; 4) temporary evacuation and housing of at-risk individuals; and 5) any emergency assistance provided under the Disaster Relief Act.

Ecological Indicator: A characteristic of the environment that, when measured, quantifies magnitude of stress, habitat characteristics, degree of exposure to a stressor, or ecological response to exposure. The term is a collective term for response, exposure. The term is a collective term for response, exposure, habitat, and stressor indicators.

Emission: Pollution discharged into the atmosphere from smokestacks, other vents, and surface areas of commercial or industrial facilities; from residential chimneys; and from motor vehicle, locomotive, or aircraft exhausts.

Emissions Trading: The creation of surplus emission reductions at certain stacks, vents, or similar emissions sources and the use of this surplus to meet or redefine pollution requirements applicable to other emission sources. This allows one source to increase emissions when another source reduces them, maintaining an overall constant emission level. Facilities that reduce emissions substantially may ?bank? their ?credits? or sell them to other industries.

Encapsulation: The treatment of asbestos-containing material with a liquid that covers the surface with a protective coating or embeds fibers in an adhesive matrix to prevent their release into the air.

Endemic: Something peculiar to a particular people or locality, such as a disease which is always present in the population.

Endrin: a pesticide toxic to freshwater and marine aquatic life that produces adverse health effects in domestic water supplies.

Environmental Assessment: An environmental analysis prepared pursuant to the National Environmental Policy Act to determine whether a federal action would significantly affect the environment and thus require a more detailed environmental impact statement.

Environmental Audit: An independent assessment (not conducted by EPA) of a facility's compliance policies, practices, and controls. Many pollution prevention initiatives require an audit to determine where wastes may be reduced or eliminated or energy conserved. Many supplemental environmental projects that offset a penalty use audits to identify ways to reduce the harmful effects of a violation.

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.

Environmental impact Statement: A document prepared by or for EPA which identifies and analyzes, in detail, environmental impacts of a proposed action. As a tool for decision-making, the EIS describes positive and negative effects and lists alternatives for an undertaking, such as development of a wilderness area. (Required by NEPA : see Federal Law Section).

Expert Witness: A person who is a specialist in a subject, often technical, who may present his or her expert opinion without having been a witness to any occurrence relating to the lawsuit.

Exposure Level (chemical): The amount (concentration) of a chemical at the absorptive surfaces of an organism.

Exposure: Radiation or pollutants that come into contact with the body and present a potential health threat. The most common routes of exposure are through the skin, mouth, or by inhalation.