Name the six criteria pollutants for which the EPA established National Ambient Air Quality Standards (NAAQS) and provide one typical source for each.

• A. Particulate matter (PM) from combustion and dust; Ozone (O3) from photochemical smog; Carbon monoxide (CO) from vehicle exhaust; Sulfur dioxide (SO2) from burning sulfur-containing fuels.
• B. Nitrogen dioxide (NO2) from wind erosion; Lead (Pb) from cooking fuels.
• C. Lead (Pb) from gasoline historically and various industrial processes.
• D. Particulate matter (PM) from combustion; Ozone (O3) from sunlight-driven chemistry; Carbon monoxide (CO) from home heating.

Answer: (D)