Environmental Terms and Definitions

Agency for Toxic Substances and Disease Registry (ATSDR)
ATSDR is part of the U.S. Department of Health and Human Services. As mandated by the federal superfund law, the agency assesses health risks from hazardous waste sites on the National Priority List.

Biological monitoring
Analyzing chemicals, hormone levels or other substances in biological materials (blood, urine, breath, etc.) as a measure of chemical exposure, health status, etc. in humans or animals. A blood test for lead is an example of biological monitoring.

ACM
Asbestos-Containing Material

Infiltration
(1) the penetration of water through the ground surface into sub-surface soil or the penetration of water from the soil into sewer or other pipes through defective joints, connections, or manhole walls. (2) a land application technique where large volumes of waste water are applied to land, allowed to penetrate the surface and percolate through the underlying soil. (See: percolation).

ADI
Acceptable Daily Intake

Analyte
A chemical for which a sample (such as water, air, blood, urine or other substance) is tested. For example, if the analyte is mercury, the laboratory test will determine the amount of mercury in the sample.

National Institute for Occupational Safety and Health (NIOSH)
NIOSH, part of the Centers for Disease Control, conducts research on worker safety and health and recommends standards for worker protection to OSHA. For example, NIOSH recommends guidelines for workplace exposure to hazardous substances and has published criteria documents on many chemicals.

Volatile organic compound (VOC)
An organic chemical that evaporates readily. Petroleum products such as kerosene, gasoline and mineral spirits contain VOCs. Chlorinated solvents such as those used by dry cleaners or contained in paint strippers are also VOCs. See "organic" and "volatile".

Interim Remedial Measure (IRM)
An action taken at a contaminated site to reduce the chances of human or environmental exposure to site contaminants. Interim remedial measures are planned and carried out before comprehensive remedial studies.

Superfund (federal and state)
The federal and state programs to investigate and clean up inactive hazardous waste sites.