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Atmospheric Pollution. Air-pollution essentialsMajor air pollutants and their sourcesImpacts of air pollutants: health and environmentBringing air pollution under controlUnresolved issues. Incorrect Assumptions about Air Pollutants. There are threshold levels of tolerable air pollutantsDilution is the solution to air pollutionAir pollutants can be assimilated by natureAir pollutants do not travelAir pollution accidents will not happen.
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1. Environmental Science: Toward a Sustainable Future Richard T. Wright Atmospheric Pollution PPT by Clark E. Adams
2. Atmospheric Pollution Air-pollution essentials
Major air pollutants and their sources
Impacts of air pollutants: health and environment
Bringing air pollution under control
Unresolved issues
3. Incorrect Assumptions about Air Pollutants There are threshold levels of tolerable air pollutants
Dilution is the solution to air pollution
Air pollutants can be assimilated by nature
Air pollutants do not travel
Air pollution accidents will not happen
4. Pollutants and Atmospheric Cleansing Air pollutants: gases and aerosols in the atmosphere that have harmful effects
Level of air pollution determined by:
The amount of pollutants entering the air
The amount of space into which the pollutants dispersed
Mechanisms that remove pollutants from the air
5. The Hydroxyl Radical: Nature’s Cleanser
6. The Appearance of Smog
7. Impacts of Smog: Temperature Inversion
8. Air Pollution Effects Adversely affects human health
Damages crops and forests
Highly corrosive
9. Major Air Pollutants and Their Sources (see Table 21-1) Suspended particulate matter
Volatile organic compounds
Carbon monoxide
Nitrogen oxides
Sulfur oxides
Heavy metals
Ozone
Air toxics
10. Major Air Pollutant Sources
11. Major Air Pollutants: Primary (see next slide) Primary pollutants derived directly from burning fuels and wastes
Particulates
Hydrocarbons
Carbon monoxide
Nitrogen oxides
Sulfur dioxides
13. Major Pollutants: Secondary (see next slide) Secondary air pollutants derive from reactions that occur between primary pollutants and other atmospheric chemicals
Ozone
PANs
Acids: sulfuric and nitric
15. Comparison of Growth vs. Emissions
17. pH Scale
19. Major Sources of SO2 Emitters
20. Impacts of Air Pollutants on Human Health Chronic: gradual deterioration of a variety of physiological functions over a period of years
Acute: life-threatening reactions within a period of hours or days
Carcinogenic: cancer-causing
21. Impacts of Air Pollutants on Human Health Chronic example: lead poisoning
Acute example: death – Bhopal, India
Carcinogenic example: lung cancer
22. The Respiratory System
24. Impacts of Air Pollutants on the Environment Plants
Necrotic: kills plant cells
Chlorotic: destroys chlorophyll, reducing photosynthesis
Increases susceptibility to disease and pests
25. Ozone Impact on Crop Yields
26. Impacts of Air Pollutants on the Environment Forests
Leaching of nutrients
Release of aluminum into solution
Rapid changes in soil chemistry
Reduced growth and diebacks of plants and animals
27. Impacts of Air Pollutants on the Environment Forests
Increased plant vulnerability to natural enemies
Increased soil erosion
Increased flooding
Increased sedimentation of waterways
28. Impacts of Air Pollutants on the Environment Materials
Loss of color
Oxidation
Corrosion
Decreased real estate values
29. Effects of Acid Deposition Alteration of plant and animal reproduction
Leaching of other toxic elements, e.g., aluminum
Eutrophic to oligotrophic conditions
Total loss of biota from aquatic ecosystems
Alterations of food chains
30. Trends in Automobile Emissions
32. Impact of Buffers on Acid Deposition
33. Bringing Air Pollution under Control Clean Air Act identifies most widespread pollutants: e.g., particulates, SO, CO, NO, lead = criteria pollutants
National Ambient Air Quality Standards (NAAQS) set levels that protect environmental and human health
34. Bringing Air Pollution under Control NAAQS: also set national ambient air quality standards
National Emission Standards for Hazardous Air Pollutants set national emission standards for hazardous air pollutants
35. Control Strategies Command-and-control: regulate air pollution so criteria pollutants remain below primary standard level
Lack of enforcement and compliance
37% reduction of air pollutants
Forced compliance with state implementation plan (SIP)
36. Match Control Strategies on Right with Air Pollutants on Left Particulates
VOCs
Automobile emissions
Acid rain Catalytic converter
Reasonably available control strategy (RACT)
Scrubbers
Coal washing
37. Title IV Clean Air Act 1990 Reduce SO emissions 50% below 1980 levels
Improve methods of reducing SO emissions
Allow emissions allowances and trading
Emissions purchases
Reduce NO emissions
38. Industry’s Response to Title IV Fuel switching
Scrubbers
Emissions allowance trading
Using low-sulfur coals
40. Unresolved Issues Costs versus benefits of air pollution control
Status of “new source” review and enforcement
Improving fuel efficiency – hybrid cars
Improving mass transit systems
Reducing commuting distances
41. End of Chapter 21