June 2009
Front Matter
Training
28
Health Risks from Air Toxics
•Simply put, health risks are a measure of the chance that you will experience health problems.
•Health risk = Hazard x exposure
•Health risk is the probability that exposure to
a hazardous substance will make you sick. 
•Exposure to toxic air pollutants can increase your health risks.
•Ambient concentrations of air toxics are compared to chronic exposure risk levels derived from scientific assessments conducted by the EPA and other environmental agencies. 
U.S. Environmental Protection Agency (2007a, b)
Animal experiments and human studies provide information about a substance’s level of hazard. Scientists use the results of such studies to estimate the likelihood of illness at different levels of exposure.
Exposure to toxic air pollutants can increase your health risks.  For example, if you live near a factory that releases cancer-causing chemicals and inhale contaminated air, your risk of getting cancer may increase. Breathing air toxics could also increase your risk of noncancer
effects such as emphysema, asthma, or reproductive disorders.
Ambient concentrations of air toxics are compared to concentrations associated with chronic exposure risk levels derived from scientific assessments conducted by the EPA and other environmental agencies.  These risk levels provide a frame of reference to put air toxics
concentrations into perspective.