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Air Pollution. Indoor/Outdoor. The Atmosphere. Troposphere. 78% N, 21% O. Stratosphere. Ozone layer. Greenhouse effect. Outdoor Air Pollution. airborne particles and gasses concentrations that endanger: heath and well-being of organisms
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Air Pollution Indoor/Outdoor
The Atmosphere • Troposphere • 78% N, 21% O • Stratosphere • Ozone layer • Greenhouse effect
Outdoor Air Pollution • airborne particles and gasses • concentrations that endanger: • heath and well-being of organisms • disrupt the orderly functioning of the environment • (1) primary pollutants: emitted directly from identifiable sources, and • (2) secondary pollutants: produced in the atmosphere when certain chemical reactions take place among primary pollutants.
Secondary Pollutants • Atmospheric sulfuric acid is one example of a secondary pollutant. • Air pollution in urban and industrial areas is often called smog. • Photochemical smog, a noxious mixture of gases and particles, is produced when strong sunlight triggers photochemical reactions in the atmosphere. • The major component of photochemical smog is ozone.
Photochemical Smog • Brown-air smog • Photochemicalreaction • Photochemicaloxidants
Regional Outdoor Air Pollution from Acid Deposition • Acid deposition • Dry deposition • Wet deposition
Acid Deposition and Humans • Respiratory diseases • Toxic metal leaching • Decreased visibility • Damage to structures, especially containing limestone • Decreased productivity and profitability of fisheries, forests, and farms
Acid Deposition and Aquatic Systems • Fish declines • Undesirable species • Aluminum toxicity • Acid shock
Acid Deposition, Plants, and Soil • Nutrient leaching • Heavy metal release • Weakens trees
Radon • Radon-222 • Occurs in certain areas based on geology • Associated with uranium and organic material in rock • 2nd most common cause of lung cancer
Air Pollution Occurrences • quantity of contaminants emitted into the atmosphere • changes in certain atmospheric conditions • (1) the strength of the wind and • (2) the stability of the air.
Air Mixing • Wind speed affects concentration of pollutants • Atmospheric stability determines extent to which vertical motions mix pollution with cleaner air above the surface layers • Mixing depth: vertical distance between Earth's surface and the height to which convectional movements extend • Greater the mixing depth, the better the air quality • Air temp differences lead to differences in air density
Inversions • Temperature inversions: atmosphere very stable and the mixing depth significantly restricted • Diffusion is inhibited and high pollution concentrations are to be expected in areas where pollution sources exist
This is an example of a generalized temperature profile for a surface inversion. Temperature-profile changes in bottom diagram after the sun has heated the surface.
Controlling Air Pollution through Regulations • Economic activity, population growth, meteorological conditions, and regulatory efforts to control emissions, all influence the trends in air pollution. • The Clean Air Act of 1970 mandated the setting of standards for four of the primary pollutants— • particulates, • sulfur dioxide, • carbon monoxide, and • Nitrogen • as well as the secondary pollutant ozone.
Key Terminology “Natural” air pollution Primary pollutants Secondary pollutants Smog Photochemical smog Ozone Clean Air Act (1970) Acid Precipitation Mixing depth Inversion Surface inversion