1. Definition of Air Toxics
2. Health and Environmental Effects
3. Sources of Air Toxics
4. Exposure to Air Toxics
5. Regulation by the EPA
6. National Air Toxics Assessment of 33 air toxics
7. 3 Examples: carbon tetrachloride, acrolein, butadiene
AKA Hazardous Air Pollutants (HAP's)
Air-borne pollutants that are known or suspected to cause cancer or
other serious health effects, such as reproductive effects or birth
defects, or to cause adverse environmental effects.
The Clean Air Act identifies 188 air toxics which are regulated by the EPA. Examples include:
Organic compounds such as Formaldehyde, Benzene, Carbon Tetrachloride, Butadiene, Acrolein
Metals such as Chromium, Mercury, Cadmium
Human Health Effects
"It has never been proven that air toxics are
hazardous to people" Tom DeLay
Increased Risk of Cancer
Respiratory Ailments
Neurological Damage
Immune System
Reproductive System, including Birth Defects
Environmental Effects
Contamination of Soils and Surface Waters
Effects on Plants and Animals
Damage to Ecosystems
Effects depend on
Quantity of toxic air polluntant
Duration and frequency of exposure
Toxicity of pollutant
Susceptibility
Mobile Sources (transportation)
Area Sources (e.g. fertilizer application)
Stationary Sources (chemical plants, oil refineries, power plants,
aerospace manufacturers, steel mills, dry cleaners, smelters,
chromium electroplating, etc.)
Breathing Contaminated Air
Eating Contaminated Food Products
Drinking Contaminated Water
Ingesting Contaminated Soil
Standards for mobile and stationary sources
Based on Maximum Achievable Control
Technology
Reduce emissions first - determine risks later
1. Emissions
Inventory
2. Modeled Ambient
Concentrations
3. Modeled Human
Exposure
4. Estimated Risk
a. Cancer Risk: n in a
million lifetime risk
b. Non-cancer Risk:
Hazard Quotient
Stable gaseous compound: residence time of 50
years
Sources
1) carbon tetrachloride production;
2) pesticide/grain fumigant usage
3) chlorinated paraffin wax production
4) fluorocarbon production
Colorless gas with mild gasoline odor
Sources: fuel production, synthetic rubber production, automobile exhaust, agricultural fungicides
Clear or yellow liquid with strong odor
Evaporates easily when heated
Sources:
Burning of trees, tobacco, other plants, gasoline, and oil
Pesticide
Chemical manufacturing
Breaks down rapidly - exposure near source
Contaminates soils, water
Respiratory effects (not a known carcinogen)
