1. Chapter 19 Air Pollution

2. Core Case Study: When Is a Lichen Like a Canary?  Lichens can warn us of bad air because they absorb it as a source of nourishment. Figure 19-1

3. Core Case Study: When Is a Lichen Like a Canary?  Some lichen species are sensitive to specific air-polluting chemicals.  After Chernobyl, more than 70,000 reindeer had to be killed because they ate highly radioactive lichens.  Because lichens are widespread, long-lived, and anchored in place, they can help track pollution to its source.

4. STRUCTURE AND SCIENCE OF THE ATMOSPHERE  The atmosphere consists of several layers with different temperatures, pressures, and compositions. Figure 19-2

5. Fig. 19-2, p. 440 Atmospheric pressure (millibars) Temperature Thermosphere Pressure Mesopause Heating via ozone Mesosphere Stratopause Altitude (kilometers) Stratosphere Altitude (miles) Tropopause Ozone “layer” Heating from the earth Troposphere Temperature (˚C) Pressure = 1,000 millibars at ground level (Sea level)

6. STRUCTURE AND SCIENCE OF THE ATMOSPHERE  The atmosphere’s innermost layer (troposphere) is made up mostly of nitrogen and oxygen, with smaller amounts of water vapor and CO 2.  Ozone in the atmosphere’s second layer (stratosphere) filters out most of the sun’s UV radiation that is harmful to us and most other species.

7. AIR POLLUTION  Some primary air pollutants may react with one another or with other chemicals in the air to form secondary air pollutants. Figure 19-3

8. Fig. 19-3, p. 442 Primary Pollutants COCO 2 Secondary Pollutants SO 2 NONO 2 Most hydrocarbons SO 3 Most suspended particles HNO 3 H2O2H2O2 O3O3 PANs Most NO 3 – and SO 4 2– salts Sources NaturalStationary Mobile H 3 SO 4

9. Major Air Pollutants  Carbon oxides: Carbon monoxide (CO) is a highly toxic gas that forms during the incomplete combustion of carbon-containing materials. Carbon monoxide (CO) is a highly toxic gas that forms during the incomplete combustion of carbon-containing materials. 93% of carbon dioxide (CO 2 ) in the troposphere occurs as a result of the carbon cycle. 93% of carbon dioxide (CO 2 ) in the troposphere occurs as a result of the carbon cycle. 7% of CO 2 in the troposphere occurs as a result of human activities (mostly burning fossil fuels). 7% of CO 2 in the troposphere occurs as a result of human activities (mostly burning fossil fuels). It is not regulated as a pollutant under the U.S. Clean Air Act.It is not regulated as a pollutant under the U.S. Clean Air Act.

10. Major Air Pollutants  Nitrogen oxides and nitric acid: Nitrogen oxide (NO) forms when nitrogen and oxygen gas in air react at the high-combustion temperatures in automobile engines and coal- burning plants. NO can also form from lightening and certain soil bacteria. Nitrogen oxide (NO) forms when nitrogen and oxygen gas in air react at the high-combustion temperatures in automobile engines and coal- burning plants. NO can also form from lightening and certain soil bacteria. NO reacts with air to form NO 2.NO reacts with air to form NO 2. NO 2 reacts with water vapor in the air to form nitric acid (HNO 3 ) and nitrate salts (NO 3 - ) which are components of acid deposition.NO 2 reacts with water vapor in the air to form nitric acid (HNO 3 ) and nitrate salts (NO 3 - ) which are components of acid deposition.

11. Major Air Pollutants  Sulfur dioxide (SO 2 ) and sulfuric acid: About one-third of SO 2 in the troposphere occurs naturally through the sulfur cycle. About one-third of SO 2 in the troposphere occurs naturally through the sulfur cycle. Two-thirds come from human sources, mostly combustion (S+ O 2  SO 2 ) of sulfur-containing coal and from oil refining and smelting of sulfide ores. Two-thirds come from human sources, mostly combustion (S+ O 2  SO 2 ) of sulfur-containing coal and from oil refining and smelting of sulfide ores. SO 2 in the atmosphere can be converted to sulfuric acid (H 2 SO 4 ) and sulfate salts (SO 4 2- ) that return to earth as a component of acid deposition. SO 2 in the atmosphere can be converted to sulfuric acid (H 2 SO 4 ) and sulfate salts (SO 4 2- ) that return to earth as a component of acid deposition.

12. Major Air Pollutants  Suspended particulate matter (SPM): Consists of a variety of solid particles and liquid droplets small and light enough to remain suspended in the air. Consists of a variety of solid particles and liquid droplets small and light enough to remain suspended in the air. The most harmful forms of SPM are fine particles (PM-10, with an average diameter < 10 micrometers) and ultrafine particles (PM-2.5). The most harmful forms of SPM are fine particles (PM-10, with an average diameter < 10 micrometers) and ultrafine particles (PM-2.5). According to the EPA, SPM is responsible for about 60,000 premature deaths a year in the U.S. According to the EPA, SPM is responsible for about 60,000 premature deaths a year in the U.S.

13. Particles: What Are They? Airborne particles are a complex mixture of extremely small solids and liquid droplets M. Lipsett, California Office of Environmental Health Hazard Assessment Human Hair (70 µm diameter) Hair cross section PM 2.5 (2.5 µm) PM 10 ( 10µm )

14. Particle Deposition  Larger particles (> PM 10 ) deposit in the upper respiratory tract  Smaller, inhalable particles (≤ PM 10 ) penetrate into the lungs  Smallest particles (ultra fines, PM 0.1 ) may enter bloodstream

15. replace

16. Fine Particulate Matter (PM 2.5 ) SO 2 & NOx NH 3 NH 3 NO 4

17. Sources of Particulate Matter  Fugitive Dust  Paved/Unpaved Roads  Agricultural Tilling  Construction Activity  Fuel Combustion  Fires  Industry  Secondary Aerosols

18. Particulate Matter  Mainly an issue during the winter time November – February November – February Inversion driven Inversion driven  Can be an issue in summer due to wildfires

19. Fine Particles are a Significant Problem 1999-2001 3-Year Average Annual Mean PM 0 < mean <= 12 12 < mean <= 15 15 < mean <= 20 Color 20 < mean Data from AQS 7/8/02. Sites that operated any time, 1999-2001 (n= 1202).

20. “Who Knows Their Particulates?”  With your partner, match the correct particulate amount with it’s source

21. Answers to Particulate Jars grams/hour  Gas Furnace or Fireplace0.00236 average  Car0.13 average  Motorcycle0.19 average  Gasoline-Powered 1.68 average  Gasoline-Powered 1.68 average Lawn Mower  Pellet Stove2.25 average  Large Diesel Truck or Bus 2.3 average  Certified Wood Stove7.5 max ( emissions from certified wood stoves are regulated, max allowed by law)  Non-Certified Wood Stove40 average  Fireplace 60 average

22. Major Air Pollutants  Ozone (O 3 ): Is a highly reactive gas that is a major component of photochemical smog. Is a highly reactive gas that is a major component of photochemical smog. It can It can Cause and aggravate respiratory illness.Cause and aggravate respiratory illness. Can aggravate heart disease.Can aggravate heart disease. Damage plants, rubber in tires, fabrics, and paints.Damage plants, rubber in tires, fabrics, and paints.

23. Ozone Formation Strong sunlight Ozon e Volatile Organic Compounds NitrogenOxidesNitrogenOxides O3O3O3O3 VOCs NO x

24. Ozone  Treasure Valley (Boise Area) Hot and sunny Hot and sunny Adequate NOx and VOCs Adequate NOx and VOCs Topography Topography # of Automobiles # of Automobiles  Summertime Air Quality issue

26. Air Quality Index and YOU!  AQI is a guide for reporting daily air quality  Identifies how clean air or polluted the air is particular areas and identifies health impacts  Focuses on what can happen within a few hours or days after breathing polluted air

27. DEQ (Department of Environmental Quality)  Uses the AQI for 5 major air pollutants: Ground-level ozone Ground-level ozone Particulate matter Particulate matter Carbon monoxide Carbon monoxide Sulfur dioxide Sulfur dioxide Nitrogen dioxide Nitrogen dioxide

28. How does the AQI work?  Values of 0-500  Value of 50 is good air quality  Value of 300 and over represents hazardous air quality

29. Color Coded Alerts  GOOD=0-50; little or no risk  MODERATE=51-100; acceptable  UNHEALTHY for SENSITIVE GROUPS=101-150  UNHEALTHY=151-200  VERY UNHEALTHY=201-300 (triggers health alert)  HAZARDOUS=over 300 (Emergency)

30. Major Air Pollutants  Volatile organic compounds (VOCs): Most are hydorcarbons emitted by the leaves of many plants and methane. Most are hydorcarbons emitted by the leaves of many plants and methane. About two thirds of global methane emissions comes from human sources. About two thirds of global methane emissions comes from human sources. Other VOCs include industrial solvents such as trichlorethylene (TCE), benzene, and vinyl chloride. Other VOCs include industrial solvents such as trichlorethylene (TCE), benzene, and vinyl chloride. Long-term exposure to benzene can cause cancer, blood disorders, and immune system damage.Long-term exposure to benzene can cause cancer, blood disorders, and immune system damage.

31. Major Air Pollutants  Radon (Rn): Is a naturally occurring radioactive gas found in some types of soil and rock. Is a naturally occurring radioactive gas found in some types of soil and rock. It can seep into homes and buildings sitting above such deposits. It can seep into homes and buildings sitting above such deposits.

32. URBAN OUTDOOR AIR POLLUTION  Industrial smog is a mixture of sulfur dioxide, droplets of sulfuric acid, and a variety of suspended solid particles emitted mostly by burning coal. In most developed countries where coal and heavy oil is burned, industrial smog is not a problem due to reasonably good pollution control or with tall smokestacks that transfer the pollutant to rural areas. In most developed countries where coal and heavy oil is burned, industrial smog is not a problem due to reasonably good pollution control or with tall smokestacks that transfer the pollutant to rural areas.

33. Sunlight plus Cars Equals Photochemical Smog  Photochemical smog is a mixture of air pollutants formed by the reaction of nitrogen oxides and volatile organic hydrocarbons under the influence of sunlight.

34. Sunlight plus Cars Equals Photochemical Smog  Mexico City is one of the many cities in sunny, warm, dry climates with many motor vehicles that suffer from photochemical smog. Figure 19-4

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

36. 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

37. 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. Tall smokestacks reduce local air pollution but can increase regional air pollution.

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

39. 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

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

41. 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.

42. ACID DEPOSITION Figure 19-8

43. 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

44. 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. Tobacco smoke. Formaldehyde. Formaldehyde. Radioactive radon-222 gas. Radioactive radon-222 gas. Very small fine and ultrafine particles. Very small fine and ultrafine particles.

45. 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

46. 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. Can cause asthma attacks and allergic reactions in some people. Figure 19-12

47. 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

48. 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

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

50. 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. 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. According to the EPA, each year more than 125,000 Americans get cancer from breathing diesel fumes.

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

52. PREVENTING AND REDUCING AIR POLLUTION  The Clean Air Acts in the United States have greatly reduced outdoor air pollution from six major pollutants: Carbon monoxide Carbon monoxide Nitrogen oxides Nitrogen oxides Sulfur dioxides Sulfur dioxides Suspended particulate matter (less than PM-10) Suspended particulate matter (less than PM-10)

53. PREVENTING AND REDUCING AIR POLLUTION  Environmental scientists point out several deficiencies in the Clean Air Act: The U.S. continues to rely on cleanup rather than prevention. The U.S. continues to rely on cleanup rather than prevention. The U.S. Congress has failed to increase fuel- efficiency standards for automobiles. The U.S. Congress has failed to increase fuel- efficiency standards for automobiles. Regulation of emissions from motorcycles and two-cycle engines remains inadequate. Regulation of emissions from motorcycles and two-cycle engines remains inadequate. There is little or no regulation of air pollution from oceangoing ships in American ports. There is little or no regulation of air pollution from oceangoing ships in American ports.

54. PREVENTING AND REDUCING AIR POLLUTION Airports are exempt from many air pollution regulations. Airports are exempt from many air pollution regulations. The Act does not regulate the greenhouse gas CO 2. The Act does not regulate the greenhouse gas CO 2. The Act has failed to deal seriously with indoor air pollution. The Act has failed to deal seriously with indoor air pollution. There is a need for better enforcement of the Clean Air Act. There is a need for better enforcement of the Clean Air Act.

55. Solutions: Reducing Outdoor Air Pollution  There are a of ways to prevent and control air pollution from coal-burning facilities. Electrostatic precipitator: are used to attract negatively charged particles in a smokestack into a collector. Electrostatic precipitator: are used to attract negatively charged particles in a smokestack into a collector. Wet scrubber: fine mists of water vapor trap particulates and convert them to a sludge that is collected and disposed of usually in a landfill. Wet scrubber: fine mists of water vapor trap particulates and convert them to a sludge that is collected and disposed of usually in a landfill.

56. Solutions: Reducing Outdoor Air Pollution  In 2003, fourteen states and a number of U.S. cities sued the EPA to block new rules that would allow older coal-burning power plants to modernize without having to install the most advanced air pollution controls.

57. Solutions: Reducing Outdoor Air Pollution  There are a of ways to prevent and control air pollution from motor vehicles. Because of the Clean Air Act, a new car today in the U.S. emits 75% less pollution than did pre- 1970 cars. Because of the Clean Air Act, a new car today in the U.S. emits 75% less pollution than did pre- 1970 cars. There is and increase in motor vehicle use in developing countries and many have no pollution control devices and burn leaded gasoline. There is and increase in motor vehicle use in developing countries and many have no pollution control devices and burn leaded gasoline.

58. Chapter Overview Questions  What layers are found in the atmosphere?  What are the major outdoor air pollutants, and where do they come from?  What are two types of smog?  What is acid deposition, and how can it be reduced?  What are the harmful effects of air pollutants?  How can we prevent and control air pollution?