Agency for Toxic
Substances and
Disease Registry
(ATSDR):
The principal federal public health agency involved with
hazardous waste issues, responsible for preventing or reducing
the harmful effects of exposure to hazardous substances on
human health and quality of life. ATSDR is part of the U.S.
Department of Health and Human Services.
Chronic:
Occurring over a long time (more than 1 year).
Comparison value
(CV):
Calculated concentration of a substance in air, water, food, or
soil that is unlikely to cause harmful (adverse) health effects in
exposed people. The CV is used as a screening level during
the public health assessment process. Substances found in
amounts greater than their CVs might be selected for further
evaluation in the public health assessment process.
Contaminant:
A substance that is either present in an environment where it
does not belong or is present at levels that might cause harmful
(adverse) health effects.
Exposure:
Contact with a substance by swallowing, breathing, or
touching the skin or eyes. Exposure may be short-term
(acute), of intermediate duration, or long-term (chronic).
Hazardous waste:
Potentially harmful substances that have been released or
discarded into the environment.
Model Toxics Control
Act (MTCA):
The hazardous waste clean-up law for Washington State.
Organic:
Compounds composed of carbon, including materials such as
solvents, oils, and pesticides which are not easily dissolved in
water.
U.S. Environmental
Protection Agency
(EPA):
Established in 1970 to bring together parts of various
government agencies involved with the control of pollution.
Volatile organic
compounds (VOCs):
Organic compounds that evaporate readily into the air. VOCs
include substances such as benzene, toluene, methylene
chloride, and methyl chloroform.
