Chapter 12.1 outline Air pollution

Clean air mostly N , and O gas with a little CO , argon and water

Harmful amount of other substances = air pollution

Can be solids, liquids or gas

Usually come from humans, can come from natural sources like volcanoes, dust, pollen, spores

Primary pollution – put directly into air by humans

Secondary pollution – form when primary pollutants combine with naturally occurring substances such as water vapor,

Ground-level Ozone – formed when emissions from vehicles react with UV rays and then mix with Oxygen

Sources of Primary Air Pollutants (see table 1, p. 304)

VOC = volatile organic compounds

CO = carbon monoxide

NO = nitrous oxides

SO = sulfur dioxide

PM = particulate matter

History of Air Pollution = whenever something is burned

Motor Vehicle Emmisions source of about 1/3 of air pollution from gasoline powered vehicles

Try to control with catalytic converters, convert HC, CO, and NO to H2O, CO2 and N2

Clean air act of 1970, strengthened in 1990

Gives the EPA, Environmental Protection Act, the authority to regulate vehicle emissions

Gradually eliminated the use of lead in gasoline 90 reduction in lead pollution

Required catalytic converters to be used

California Zero-emmisions vehicle program by the California Air Resources Board

Promotes vehicles that have no emissions from gasoline

16% goal by 2016, use electric or natural gas (methanol)

Industrial Air pollution –

Power plants Sulfur dioxide and nitrogen oxides

VOC = toxic fumes

Dry cleaning, oil refineries, chemical plants, furniture finishers, automobile repair shops

Regulating industrial air pollution

Clean air act requires some to use scrubbers or other pollution control devices

Scrubbers – spray of water that removes many pollutants

Electrostatic precipitators – remove dust particles from cement or coal fired power plants

Smog – visible pollution over urban areas, auto exhaust, sunlight, air, ozone

Temperature inversions – air above is warmer than the air below, this traps pollutants near the earth’s surface sometimes caused by surrounding mountains