Environmental Health Definitions

VOLATILE ORGANIC COMPOUND
The class of chemical compounds originally coming from plants or animals, and made primarily of carbon and hydrogen. These chemicals are released into the air during evaporation.
ACUTE EFFECTS
Health effects that occur immediately or soon after exposure to, in this case, chemicals. Examples range from irritation to the eyes, nose, throat, lungs and skin, through to death, depending on several factors.
SUBACUTE EFFECTS
Response to central nervous system damage which can include headache, drowsiness, confusion, irritability, loss of coordination, loss of concentration, tremors,
convulsion, etc.
CHRONIC EFFECTS
Long term effects, usually after repeated exposures or one sizeable exposure. Some of these effects of chronic toxicity can be in the form of cancer, heart attacks, stroke, high blood pressure, lung problems, immune system suppression, liver damage and birth defects.
CARCINOGEN
A substance that can cause or contribute to cancer. Some chemicals on the EPA’s list of human carcinogens and suspected carcinogens are: benzene, methylene chloride, chloroform, formaldehyde, trichloroethylene, and tetrachloroethylene.
EXPOSURE
Contact with a chemical by swallowing, by breathing or by direct contact (such as through the skin or eyes). Chemicals can be absorbed through the skin into the bloodstream and then transported to other organs, and can also be absorbed into the bloodstream after breathing or swallowing.
MULTIPLE CHEMICAL SENSITIVITY
A condition in which a person is considered to be sensitive to a number of chemicals at very low concentrations and which is marked by severe and debilitating
reactions.
SENSITIZATION
An allergic condition that usually affects the skin or lungs, but can also affect the immune system. Once exposure to a substance has caused a reaction, the individual may be sensitized to it, and further exposure may elicit an adverse reaction even at low levels.
SYNERGISM
The cooperative interaction of two or more chemicals producing a greater total effect than the sum of their individual effects. It is suspected by researchers that multiple chemicals can have a greater health effect on an individual than one chemical, depending upon the concentration.
BODY BURDEN
The total amount of a chemical accumulated in the body which can be stored in body organs such as fat or bone, and in brain tissue.
Canadians for A Safe Learning Environment 
Reference: Indoor Air Quality in Schools. Cutter Information Corporation. 1996.