Category | Examples |
Metals | lead, arsenic, mercury |
VOCs | trichloroethylene, toluene, benzene, chloroform, tetrachloroethylene, 1,1,1-trichloroethane methylene chloride, ethylbenzene, xylene, vinyl chloride, carbon tetrachloride |
Halogenated pesticides and related compounds | DDT, PCBs |
PAHs | benzo(a)pyrene |
Radionuclides | |
Biological wastes |
Group | Exposure | Demographics |
Industrial workers | Acute & chronic exposure to industrial chemicals | Primarily male, blue collar, aged 20-65 |
Tight building occupants | Off-gassing from construction materials; office equipmentor supplies; tobacco smoke; inadequate ventilation | F>M; White-collar and professional workers aged 20-65 and schoolchildren |
Contaminated communities | Toxic waste sites; aerial pesticide spraying; ground-water and air contamination by nearby industry and other community exposure | M and F; all ages; children and infants may be affected first and/or most severely; middle-lower class |
Individuals | Heterogeneous: indoor air (domestic), consumer products, drugs pesticides | 70-80% female; mostly in 30-50 age range; white; middle class and professional |
Cl + O3 ClO + O2 ClO + O Cl + O2 |
GREENHOUSE GASES AND WHERE THEY COME FROM |
Atmospheric Concentrations |
Gas Source Pre-Industrial 1990 Change |
Water vapor |
CO2 Combustion 280 ppm 353 ppm 1.8 ppm/yr |
CH4 Combustion peat, rice cultivation, cow flatus 800 ppb 1720 ppb 15 ppb/yr |
N2O Combustion 288 ppb 310 ppb 0.8 ppb/yr |
CFCs Industrial production 0300-500 ppt 10-17 ppt/yr |
Ozone Automobiles |