Chapter 24 Air Pollution

Stationary and Mobile Sources of Air Pollution Two Sources of Air Pollution 1. Stationary Sources: have a relatively fixed location Point Sources Fugitive Sources Area Sources 2. Mobile Sources: move from place to place while emitting pollutants Ex) Airplanes

General Effects of Air Pollution Visual quality of the environment Vegetation, Animals, Soil Water Quality Natural and Artificial Structures Human Heath

Primary and Secondary Pollutants, Natural and Human Primary Pollutants –Those emitted directly into the air –Hydrocarbons, particulates, etc. Secondary Pollutants –Produced through reactions between primary pollutants and normal atmospheric compounds –Ozone

Major Air Pollutants Sulfur Dioxide (acid rain) Nitrogen Oxide Carbon Monoxide Ozone and Other Photochemical Oxidants Volatile Organic Compounds Particulate Matter Hydrogen Sulfide Hydrogen Fluoride Hazardous Gases Lead

Acid Rain Causes: –sulfur dioxide –nitrogen oxides transformed by reactions with O rainfall, snow, fog dry deposition power plants

Implications of Acid Rain Forest ecosystems –loss of soil nutrients –loss of habitat Lake ecosystems –disrupts life processes –biomagnification Human Society

Urban Air Pollution Potential for Air Pollution Determined by: –Rate of emission –Downwind distance –Average wind speed –Elevation Atmospheric Inversion: –Occurs when warmer air is found above cooler air and it poses a particular problem when there is a stagnant air mass –meteorology and topography

Smog –A mixture between smoke and fog that produces unhealthy urban air Two Types –Photochemical Smog –Sulfurous Smog

Arctic Haze Pollutants (sulfates, carbon soot, toxic metals..) Elevated levels of CO, CO2 & methane E. Europe, Russia, U.K., W. Europe U.S.

Future Trends for Urban Areas United States –stricter emission controls –improve public transportation –Los Angeles Developing Countries –lack financial base –housing and food of greater concern –Mexico City

Pollution Control Particulates Automobiles Sulfur Dioxide –Coal Gasification: converts coal to gas to remove sulfur –Scrubbing: gas desulfurization

Air Pollution: Legislation and Standards Clean Air Act Amendments of 1990 –Comprehensive regulations enacted by U.S congress that address acid rain, toxic emissions, ozone depletion and automobile exhaust Air Quality Standards –Attempt to control air pollution Tougher Standards for PM 2.5 and Ozone Air Quality Index