Atmospheric Pollution

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

6. Major Air Pollutant Sources

7. 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 Sources of Air Pollution

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 IndoorAir 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. TheRespiratorySystem

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. Particulates VOCs Automobile emissions Acid rain Catalytic converter Reasonably available control strategy (RACT) Scrubbers Coal washing Can you Match Control Strategies on Right with Air Pollutants on Left?

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!