1. Ch 19 Acid Rain Acid rain Outdoor/ Indoor Pollution

2. Factors Influencing Levels of Outdoor Air Pollution Outdoor air pollution can be reduced by: – settling out, precipitation, sea spray, winds, and chemical reactions. Outdoor air pollution can be increased by: – urban buildings (slow wind dispersal of pollutants), mountains (promote temperature inversions), and high temperatures (promote photochemical reactions).

3. Temperature Inversions Cold, cloudy weather in a valley surrounded by mountains can trap air pollutants (left). Areas with sunny climate, light winds, mountains on three sides and an ocean on the other (right) are susceptible to inversions. Figure 19-5

4. Fig. 19-5, p. 447 Warmer air Descending warm air mass Inversion layer Sea breeze Increasing altitude Decreasing temperature PLAY VIDEO

5. ACID DEPOSITION Sulfur dioxides, nitrogen oxides, and particulates can react in the atmosphere to produce acidic chemicals that can travel long distances before returning to the earth’s surface. – Tall smokestacks reduce local air pollution but can increase regional air pollution.

6. Animation: Acid Deposition PLAY ANIMATION

7. ACID DEPOSITION Acid deposition consists of rain, snow, dust, or gas with a pH lower than 5.6. Figure 19-6

8. Fig. 19-6, p. 448 Wind Transformation to sulfuric acid (H 2 SO 4 ) and nitric acid (HNO 3 ) Windborne ammonia gas and particles of cultivated soil partially neutralize acids and form dry sulfate and nitrate salts Wet acid depostion (droplets of H 2 SO 4 and HNO 3 dissolved in rain and snow) Nitric oxide (NO) Sulfur dioxide (SO 2 ) and NO Dry acid deposition (sulfur dioxide gas and particles of sulfate and nitrate salts) Acid fog Farm Ocean Lakes in deep soil high in limestone are buffered Lakes in shallow soil low in limestone become acidic

9. ACID DEPOSITION pH measurements in relation to major coal- burning and industrial plants. Figure 19-7

10. ACID DEPOSITION Acid deposition contributes to chronic respiratory disease and can leach toxic metals (such as lead and mercury) from soils and rocks into acidic lakes used as sources for drinking water.

11. ACID DEPOSITION Figure 19-8

12. ACID DEPOSITION Air pollution is one of several interacting stresses that can damage, weaken, or kill trees and pollute surface and groundwater. Figure 19-9

13. Fig. 19-9, p. 451 Emissions SO 2 NO x Acid deposition H2O2H2O2 O3O3 Others Direct damage to leaves & bark Reduced photo- synthesis and growth Susceptibility to drought, extreme cold, insects, mosses, & disease organisms Soil acidification Tree death Leaching of soil nutrients Release of toxic metal ions Root damage Reduced nutrient & water uptake Acids Lake Groundwater PANs

14. Animation: Effects of Air Pollution in Forests PLAY ANIMATION

15. Fig. 19-10, p. 452 Solutions Acid Deposition PreventionCleanup Reduce air pollution by improving energy efficiency Add lime to neutralize acidified lakes Reduce coal use Add phosphate fertilizer to neutralize acidified lakes Increase natural gas use Increase use of renewable energy resources Burn low-sulfur coal Remove SO 2 particulates & NO x from smokestack gases Remove NO x from motor vehicular exhaust Tax emissions of SO 2

16. INDOOR AIR POLLUTION Indoor air pollution usually is a greater threat to human health than outdoor air pollution. According to the EPA, the four most dangerous indoor air pollutants in developed countries are: – Tobacco smoke. – Formaldehyde. – Radioactive radon-222 gas. – Very small fine and ultrafine particles.

17. Chloroform Benzo-  -pyrene Styrene Radon-222 Methylene Chloride Tobacco Smoke Carbon Monoxide Asbestos Nitrogen Oxides 1, 1, 1- Trichloroethane Particulates FormaldehydeTetrachloroethylene Para-dichlorobenzene Fig. 19-11, p. 453

18. Interactive Home PLAY ANIMATION

19. PVC Exposure PLAY VIDEO

20. INDOOR AIR POLLUTION Household dust mites that feed on human skin and dust, live in materials such as bedding and furniture fabrics. – Can cause asthma attacks and allergic reactions in some people. Figure 19-12 PLAY VIDEO

21. Case Study: Radioactive Radon Radon-222, a radioactive gas found in some soils and rocks, can seep into some houses and increase the risk of lung cancer. Sources and paths of entry for indoor radon-222 gas Sources and paths of entry for indoor radon-222 gas. Figure 19-13

22. Fig. 19-13, p. 454 Outlet vents for furnaces and dryers Open window Openings around pipes Cracks in wall Slab joints Wood stove Cracks in floor Clothes dryer Sump pump Furnace Slab Radon-222 gas Uranium-238 Soil

23. HEALTH EFFECTS OF AIR POLLUTION Your respiratory system can help protect you from air pollution, but some air pollutants can overcome these defenses. Figure 19-14

24. Fig. 19-14, p. 455 Epithelial cell Cilia Nasal cavity Oral cavity Goblet cell (secreting mucus) Pharynx (throat) Mucus Trachea (windpipe) Bronchus Bronchioles Right lung Bronchioles Alveolar sac (sectioned) Alveoli Alveolar duct PLAY VIDEO

25. HEALTH EFFECTS OF AIR POLLUTION Normal human lungs (left) and the lungs of a person who died of emphysema (right). Figure 19-15

26. Air Pollution is a Big Killer Each year, air pollution prematurely kills about 3 million people, mostly from indoor air pollution in developing countries. – In the U.S., the EPA estimates that annual deaths related to indoor and outdoor air pollution range from 150,000 to 350,000. – According to the EPA, each year more than 125,000 Americans get cancer from breathing diesel fumes.

27. Air Pollution is a Big Killer Spatial distribution of premature deaths from air pollution in the United States. Figure 19-16

28. Video: Air Pollution in China  The Daily Show with Jon Stewart PLAY VIDEO