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Air Pollution, Climate Change, and Ozone Depletion

Air Pollution, Climate Change, and Ozone Depletion

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Air Pollution, Climate Change, and Ozone Depletion

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  1. Air Pollution, Climate Change, and Ozone Depletion Chapter 15

  2. 15-1 What Are the Major Air Pollution Problems? (1) • Concept 15-1A Three major outdoor air pollution problems are industrial smog from burning coal, photochemical smog from motor vehicle and industrial emissions, and acid deposition from coal burning and motor vehicle exhaust.

  3. 15-1 What Are the Major Air Pollution Problems? (2) • Concept 15-1B The most threatening indoor air pollutants are smoke and soot from wood and coal fires (in developing countries) and chemicals used in building materials and products (in developed countries).

  4. Earth’s Atmosphere • Troposphere(對流層) • 75–80% earth’s air mass • 78% N2, 21% O2 • Stratosphere(平流層) Ozone layer----好的 臭氧 約海平面上17-30km

  5. Layering of the Earth’s Atmosphere

  6. Temperature Pressure Thermosphere Mesopause Mesosphere Stratopause Stratosphere Tropopause Ozone layer Troposphere Fig. 15-2, p. 346

  7. Outdoor Air Pollution • What is air pollution? 污染物濃度高到足以傷害生物或物質 並使氣候產生變化 • Outdoor and Indoor air pollution • Natural and Human Sources* • Stationary and mobile sources* 固定污染源 移動污染源 • Primary pollutants (初級污染物)(一次污染物) • Secondary pollutants (次級污染物)(二次污染物)

  8. Mount Pinatubo in the Philippines on June 12, 1991 Fig. 15-1, p. 344

  9. Core Case Study: Volcanoes and Climate Change • Study volcano to understand climate change • Mount Pinatubo – 1991 • Second largest volcanic eruption of 20th century (the largest----Alaska, 1912) • Massive release of air pollution globally • Opportunity to test climate models • Predictions matched observations

  10. Sources and Types of Air Pollutants

  11. Primary Pollutants CO CO2 Secondary Pollutants SO2 NO NO2 SO3 Most hydrocarbons HNO3 H2SO4 Most suspended particles H2O2 O3 PANs Most NO3– and SO42– salts Sources Natural Stationary Mobile Fig. 15-3, p. 347

  12. Types of Major Air Pollutants • Carbon oxides (CO, CO2) • Nitrogen oxides and nitric acid (NO, NO2, HNO3) • Sulfur dioxide and sulfuric acid (SO2, SO3, H2SO4) • Particulates (SPM--- suspended particulate matter) • Ozone (O3) • Volatile organic compounds (VOCs) • Radioactive radon (Rn) 氡

  13. Science Focus: Using Lichens(地衣) to Detect Air Pollution • Indicators of air pollution* • Mine canaries---金絲雀偵測甲烷 • Lichens (真菌+藻類的共生物) • Isle Royale in Lake Superior (蘇必略湖 羅耀拉島 有二氧化硫污染 利用地衣指出污染源 來自加拿大桑德灣的燃煤工廠)

  14. Lichens Growing on Slate Rock Fig. 15-A, p. 348

  15. Industrial Smog ( gray-air smog)工業煙霧 • Burning coal in power plants and factories • Sulfur dioxide, sulfuric acid, suspended particles • Developed versus developing countries • Air pollution control in the U.S. and Europe • China, India, Ukraine, Eastern Europe (no air pollution control)

  16. Photochemical Smog 光化學煙霧 • Photochemical reactions* • Photochemical smog • Brown-air smog (reddish-brown NO2)

  17. Photochemical Smog • A mixture of primary and secondary pollutants. Forms when primary pollutants interact under the influence of sunlight. • Two most destructive components: • Ozone • Peroxyacetyl Nitrates (過氧乙醯硝酸鹽) (PAN) • Large cities ringed by mountains tend to have trouble with photochemical smog.*

  18. Daily Changes in Photochemical Smog

  19. Natural Factors That Reduce Air Pollution • Particles heavier than air • Rain and snow • Salty sea spray from oceans • Winds • Chemical reactions (ex. SO2→ SO3 → H2SO4 → acid rain → land)

  20. Natural Factors That Increase Air Pollution • Urban buildings • Hills and mountains • High temperatures • VOC emissions from certain trees and plants • Grasshopper effect (跳躍式的傳播) (極地生物體出現DDT, PCBs, Pb, Hg) • Temperature inversions (溫度逆轉)*

  21. Thermal Inversion

  22. Acid Deposition 酸性沉降 • Sulfur dioxides and nitrogen oxides* • Wet and dry deposition • Acid rain (pH<5.6) • Regional air pollution* • Coal-burning power plants • Prevailing winds

  23. Acid Deposition

  24. Wind Transformation to sulfuric acid (H2SO4) and nitric acid (HNO3) Windborne ammonia gas and some soil particles partially neutralize acids and form dry sulfate and nitrate salts Wet acid deposition (droplets of H2SO4 and HNO3 dissolved in rain and snow) Nitric oxide (NO) Sulfur dioxide (SO2) and NO Dry acid deposition (sulfur dioxide gas and particles of sulfate and nitrate salts) Acid fog Lakes in shallow soil low in limestone become acidic Lakes in deep soil high in limestone are buffered Fig. 15-4, p. 351

  25. Current and Potential Problems with Acid Deposition Fig. 15-5, p. 351

  26. Harmful Effects of Acid Deposition • Respiratory diseases in humans* • Toxic metal leaching from soils and rocks • Structural damage* • Kills fish and other aquatic organisms* • Leaches plant nutrients from soil* • Acid clouds and fog at mountaintops*

  27. Healthy and Diseased Lungs Fig. 15-10, p. 356

  28. Impacts of Air Pollution on Trees and Water

  29. Emissions SO2 H2O2 PANs NOx Acid deposition O3 Others Reduced photosynthesis and growth Increased susceptibility to drought, extreme cold, insects, mosses, and disease organisms Direct damage to leaves and bark Soil acidification Tree death Leaching of soil nutrients Root damage Release of toxic metal ions Reduced nutrient and water uptake Acids Lake Groundwater Fig. 15-6, p. 353

  30. Reducing Acid Deposition Fig. 15-7, p. 353

  31. Indoor Air Pollution • Often higher concentration in buildings and cars (in buildings 2-5 times, in cars 18 times) • Most time is spent indoors or in cars (70-98% of time) • EPA – top cancer risk • Sick-building syndrome (SBS) (dizziness, headaches, coughing, nausea etc.)

  32. Major Indoor Air Pollutants In Developed Countries* • Tobacco smoke • Formaldehyde (甲醛, HCHO) • Radioactive radon-222 gas • Very small particles In Developing Countries • Particulates ←Indoor cooking and heating

  33. Important Indoor Air Pollutants

  34. Tetrachloroethylene Source: Dry-cleaning fluid fumes on clothes Threat: Nerve disorders, damage to liver and kidneys, possible cancer Para-dichlorobenzene Source: Air fresheners, mothball crystals Threat: Cancer Chloroform Source: Chlorine-treated water in hot showers Possible threat: Cancer Formaldehyde Source: Furniture stuffing, paneling, particleboard, foam insulation Threat: Irritation of eyes, throat, skin, and lungs; nausea; dizziness 1,1,1-Trichloroethane Source: Aerosol sprays Threat: Dizziness, irregular breathing Styrene Source: Carpets, plastic products Threat: Kidney and liver damage Nitrogen oxides Source: Unvented gas stoves and kerosene heaters, woodstoves Threat: Irritated lungs, children's colds, headaches Benzo-α-pyrene Source: Tobacco smoke, woodstoves Threat: Lung cancer Particulates Source: Pollen, pet dander, dust mites, cooking smoke particles Threat: Irritated lungs, asthma attacks, itchy eyes, runny nose, lung disease Radon-222 Source: Radioactive soil and rock surrounding foundation, water supply Threat: Lung cancer Tobacco smoke Source: Cigarettes Threat: Lung cancer, respiratory ailments, heart disease Methylene chloride Source: Paint strippers and thinners Threat: Nerve disorders, diabetes Asbestos Source: Pipe insulation, vinyl ceiling and floor tiles Threat: Lung disease, lung cancer Carbon monoxide Source: Faulty furnaces, unvented gas stoves and kerosene heaters, woodstoves Threat: Headaches, drowsiness, irregular heartbeat, death Fig. 15-8, p. 354

  35. Air Pollution and the Human Respiratory System* • Natural protective system • Lung cancer, chronic bronchitis (慢性支氣管炎), emphysema (肺氣腫), asthma (氣喘) • Premature deaths* • Fossil fuels • Coal • Diesel engines

  36. Human Respiratory System

  37. Epithelial cell Cilia Nasal cavity Goblet cell (secreting mucus) Oral cavity Pharynx (throat) Mucus Trachea (windpipe) Bronchioles Bronchus Alveolar duct Right lung Bronchioles Alveoli Alveolar sac (sectioned) Fig. 15-9, p. 355

  38. Healthy and Diseased Lungs Fig. 15-10, p. 356

  39. 15-2 How Should We Deal with Air Pollution? • Concept 15-2 Legal, economic, and technological tools can help clean up air pollution, but scientists call for much greater emphasis on preventing air pollution.

  40. U.S. Outdoor Air Pollution Control Laws • Clean Air Acts • National Ambient Air Quality Standards (EPA) Criteria pollutants (CO, NO, SO2, PM, O3, Pb) • Emission Standards for Hazardous Air Pollutants • Good news Emission of pollutants decreased by 53% Pb︰ -99% (1970-2005) • Bad news Unaccepted level of ground-level ozone

  41. Improving Air Pollution Laws • Emphasize pollution prevention • Increase fuel economy standards • Regulate emissions from two-cycle engines • Regulate ocean-going ships • Increase regulations at airports • Specifically regulate CO2 • Increase regulations for indoor air pollution • Better enforcement of Clean Air Act

  42. Using the Marketplace to Reduce Air Pollution • Emissions trading (cap and trade) program 排放量交易計畫 • Proponents – cheaper and more efficient • Critics – companies buy their way out • Success depends on cap (限量) • Good news—Reduce SO2 emission by 31% (1990→2005) • Bad news—far short of projected emissions reduction

  43. Solutions: Stationary Source Air Pollution Fig. 15-12, p. 358

  44. Solutions: Motor Vehicle Air Pollution Fig. 15-13, p. 359

  45. Solutions: Indoor Air Pollution Fig. 15-14, p. 359

  46. What Can You Do? Fig. 15-15, p. 360