1. Atmospheric Pollution

2. Pollutants and Atmospheric Cleansing
Air pollutants: gases and aerosols in the atmosphere that have harmful effects
Living organisms
Inanimate objects
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

3. Myths about Air Pollutants
There are tolerable threshold levels of 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. The Hydroxyl Radical: Nature’s Cleanser

5. Major Air Pollutants Carbon monoxide & dioxide
Suspended particulate matter
Volatile organic compounds
Nitrogen oxides & Sulfur oxides
Ozone
Hazardous Air Pollutants
Heavy metals
Volatile Organic Compounds
Herbicides & Pesticides

6. Major Air Pollutant Sources

7. Sources of Air Pollution
Automobiles
Burning Fossil Fuels -->CO, CO2, Particulates, Metals, and NOx
Transporting Fossil Fuels --> VOCs & HAPs
Secondary Pollutants --> O3
Coal Power Plants
Exhaust --> CO, CO2, Particulates, Metals, NOx, SO2, & HAPs (metals, radioactive nucleotides, and VOCs)
Industrial Processes (chemical, dry cleaning, printing, paints, glues, solvents, agriculture)
Manufacturing --> HAPs, VOCs, Metals, CFCs
Waste --> SO2, Particulates, VOCs, HAPs, and O3

8. Sources of Major Air Pollutants
Automobiles
Power Plants
Industrial Processes
Primary pollutants derived directly from burning fuels and wastes
Sulfur dioxides
Nitrogen oxides
Volatile Organic Compounds
Particulates
Carbon monoxide

9. Major Pollutants: Secondary
Secondary air pollutants are derived from reactions that occur between primary pollutants and other atmospheric chemicals
Ozone
PANs
Acids
Sulfuric
nitric

10. Examining Specific Air Pollutants
Indoor Air Pollution
Smog
Acid Precipitation

11. Indoor Air Pollution

12. Radon Radioactive radon-222 Lung Cancer Threat
Occurs in certain geological areas
Associated with Uranium and organic materials in rock

13. Reducing Indoor Air Pollution

14. Smog The most visible air pollution Two types of smog
Brown photochemical
Gray industrial
Directly linked to human behavior

15. Impacts of Smog: Temperature Inversion

16. Particulates

17. Comparison of Growth vs. Emissions

18. Acid Deposition

19. pH Scale pH = measurement of H+ ions in solution
Acid precipitation = pH <5.5

22. Major Sources of SO2 Emitters

23. 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

25. Impact of Buffers on Acid Deposition

26. Solutions to Acid Deposition

27. Air Pollution Effects Adversely affects the health of organisms
People
Other Animals
Crops
Forests
Highly corrosive to Structures
Metal
Stone

28. 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

29. Impacts of Air Pollutants on Human Health
The Respiratory System
Chronic Bronchitis and Asthma
Lung Cancer
Brain
Birth defects, retardation, & nervous system disorders
Short- & Long-term memory loss
Brain Cancer
Filtering Organs (Liver & Kidneys)
Short-term disfunction
Cancer
Skin
Overexposure to UV --> Cancer

30. The Respiratory System

32. Impacts of Air Pollutants on the Environment
Plants
Necrotic: kills plant cells
Chlorotic: destroys chlorophyll, reducing photosynthesis
Increases susceptibility to disease and pests
Ozone is the most serious pollutant to Plants

33. Ozone Impact on Crop Yields

34. 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
Increased plant vulnerability to natural enemies
Increased soil erosion
Increased flooding
Increased sedimentation of waterways

35. Impacts of Air Pollutants on the Environment
Building Materials
Loss of color
Oxidation
Corrosion
Decreased real estate values

36. Trends in Automobile Emissions

37. 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

38. Bringing Air Pollution under Control
NAAQS = national ambient air quality standards (EPA)
National Emission Standards for Hazardous Air Pollutants set national emission standards for hazardous air pollutants

39. 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)

40. Can you 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

41. 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

42. Industry’s Response to Title IV
Fuel switching
Scrubbers
Emissions allowance trading
Using low-sulfur coals

43. Reducing Emissions from Point Sources

44. Reducing Motor Vehicle Air Pollution

45. Unresolved Issues Costs vs benefits of air pollution control
Status of “new source” review & enforcement
Improving fuel efficiency – hybrid cars
Improving mass transit systems
Reducing commuting distances
Should the EPA regulate CO2 as a pollutant?
Research this question! Come prepared to discuss your findings in class tomorrow!