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Air Pollution

Air Pollution. Chapter 18. Core Case Study: South Asia’s Massive Brown Cloud. Asian Brown Cloud Causes Chemical composition Areas impacted Air pollution connects the world Steps taken in China and India to reduce air pollution. The Asian Brown Cloud.

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Air Pollution

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  1. Air Pollution Chapter 18

  2. Core Case Study: South Asia’s Massive Brown Cloud • Asian Brown Cloud • Causes • Chemical composition • Areas impacted • Air pollution connects the world • Steps taken in China and India to reduce air pollution

  3. The Asian Brown Cloud

  4. Air Pollution in Shanghai, China, in 2004

  5. 18-1 What Is the Nature of the Atmosphere? • Concept 18-1 The atmosphere is structured in layers, including the troposphere, which supports life, and the stratosphere, which contains the protective ozone layer.

  6. The Atmosphere Consists of Several Layers • Atmosphere varies in • Density • Atmospheric pressure

  7. Air Movements in the Troposphere Play a Key Role in Earth’s Weather and Climate • Troposphere • 75–80% of the earth’s air mass • Closet to the earth's surface • Chemical composition of air • Rising and falling air currents: weather and climate • Involved in chemical cycling

  8. The Stratosphere Is Our Global Sunscreen • Stratosphere • Similar composition to the troposphere, with 2 exceptions • Much less water • O3, ozone layer, filters UV • Location

  9. Natural Capital: The Earth’s Atmosphere Is a Dynamic System with Four Layers

  10. Atmospheric pressure (millibars) 1,000 200 0 400 600 800 120 75 Temperature 110 65 Thermosphere 100 90 55 Mesopause 80 Mesosphere 45 70 Altitude (kilometers) Altitude (miles) 60 Stratopause 35 50 Stratosphere 40 25 30 Tropopause 15 Ozone layer 20 10 Pressure Troposphere 5 (Sea level) 0 Pressure = 1,000 millibars at ground level –80 80 40 120 –40 0 Temperature (˚C) Fig. 18-3, p. 470

  11. 18-2 What Are the Major Outdoor Pollution Problems? • Concept 18-2 Pollutants mix in the air to form industrial smog, mostly the result of burning coal, and photochemical smog, caused by motor vehicle, industrial, and power plant emissions.

  12. Air Pollution Comes from Natural and Human Sources (1) • Air pollution • Natural sources • Dust blown by wind • Pollutants from wildfires and volcanoes • Volatile organics released by plants • Withdrawing groundwater

  13. Air Pollution Comes from Natural and Human Sources (2) • Human sources: mostly in industrialized and/or urban areas • Stationary sources • Mobile sources

  14. Case Study: Air Pollution in the Past: The Bad Old Days (1) • Discovery of fire • Middle Ages • Industrial Revolution • London, England • 1850s • 1952: yellow fog • Clean Air Act of 1956

  15. Case Study: Air Pollution in the Past: The Bad Old Days (2) • United States • 1948: Donora, PA; first U.S. air pollution disaster • 1963: New York City • Global problem

  16. Some Pollutants in the Atmosphere Combine to Form Other Pollutants • Primary pollutants • Secondary pollutants • Air quality improving in developed countries • Much more needs to be done in developing countries • Indoor pollution: big threat to the poor

  17. Sources and Types of Air Pollutants

  18. Primary Pollutants Secondary Pollutants CO CO2 SO2 NO NO2 SO3 Most hydrocarbons HNO3 H2SO4 Most suspended particles H2O2 O3 PANs Most NO3− and SO42− salts Sources Natural Stationary Mobile Fig. 18-4, p. 472

  19. Indoor Air Pollution

  20. What Are the Major Outdoor Air Pollutants? (1) • Carbon oxides • Carbon monoxide (CO) • Carbon dioxide (CO2) • Sources • Human health and environmental impact

  21. What Are the Major Outdoor Air Pollutants? (2) • Nitrogen oxides (NO) and nitric acid (HNO3) • Sources • Acid deposition • Photochemical smog • Human health and environmental impact • Sulfur dioxide (SO2) and sulfuric acid (H2SO4) • Sources • Human health and environmental impact

  22. What Are the Major Outdoor Air Pollutants? (3) • Particulates • Suspended particulate matter (SPM) • Fine • Ultrafine • Sources • Human health and environmental impact

  23. What Are the Major Outdoor Air Pollutants? (4) • Ozone (O3) • Sources • Human and environmental impact • Volatile organic compounds (VOCs) • Hydrocarbons and terpenes • Sources • Human and environmental impact

  24. Chemical Reactions That Form Major Outdoor Air Pollutants

  25. Stepped Art Table 18-1, p. 473

  26. Statue Corroded by Acid Deposition and Other Forms of Air Pollution, RI, U.S.

  27. Science Focus: Detecting Air Pollutants • Chemical instruments • Satellites • Nanotechnology • Biological indicators • Lichens

  28. Natural Capital: Lichen Species, Vulnerability to Air Pollutants

  29. Case Study: Lead Is a Highly Toxic Pollutant (1) • Does not break down in the environment • Sources • Human health and environmental impact • Most vulnerable

  30. Case Study: Lead Is a Highly Toxic Pollutant (2) • Reduction of lead (Pb) • Unleaded gasoline • Unleaded paint • Still problems • 2007: toys with Pb paint recalled • Global ban on lead in gasoline and paint

  31. Solutions: Lead Poisoning, Prevention and Control

  32. SOLUTIONS Lead Poisoning Prevention Control Replace lead pipes and plumbing fixtures containing lead solder Phase out leaded gasoline worldwide Phase out waste incineration Remove leaded paint and lead dust from older houses and apartments Ban use of lead solder Sharply reduce lead emissions from incinerators Ban use of lead in computer and TV monitors Remove lead from TV sets and computer monitors before incineration or land disposal Ban lead glazing for ceramicware used to serve food Test for lead in existing ceramicware used to serve food Ban candles with lead cores Test existing candles for lead Test blood for lead by age 1 Wash fresh fruits and vegetables Fig. 18-7, p. 476

  33. Burning Coal Produces Industrial Smog • Chemical composition of industrial smog • Reduction of this smog in urban cities of the United States • China and smog • Human deaths

  34. How Pollutants Are Formed from Burning Coal and Oil, Leading to Industrial Smog

  35. Ammonium sulfate [(NH4)2SO4] Ammonia (NH3) Sulfuric acid (H2SO4) Carbon monoxide (CO) and carbon dioxide (CO2) Water vapor (H2O) Sulfur trioxide (SO 3 ) Oxygen (O2) Sulfur dioxide (SO2) Burning coal and oil Oxygen (O2) Carbon (C) in coal and oil Sulfur (S) in coal and oil Fig. 18-8, p. 476

  36. Ammonium sulfate [(NH4)2SO4] Ammonia (NH3) Sulfuric acid (H2SO4) Carbon monoxide (CO) and carbon dioxide (CO2) Water vapor (H2O) Sulfur trioxide (SO 3 ) Oxygen (O2) Sulfur dioxide (SO2) Burning coal and oil Oxygen (O2) Carbon (C) in coal and oil Sulfur (S) in coal and oil Stepped Art Fig. 18-8, p. 476

  37. Sunlight Plus Cars Equals Photochemical Smog • Photochemical Smog • Chemical composition • Sources • VOCs + NO2 + Heat + Sunlight yields • Ground level O3 and other photochemical oxidants • Aldehydes • Other secondary pollutants • Human health and environmental impact

  38. A Model of How Pollutants That Make Up Photochemicals Are Formed

  39. PANS and other pollutants Volatile organic compounds (VOCs) Ozone (O3) Oxygen (O2) Nitric oxide (NO) + Oxygen atom (O) Water vapor (H2O) Hydrocarbons UV radiation Peroxyacyl nitrates (PANs) Nitrogen dioxide (NO2) Oxygen (O2) Nitric oxide (NO) Oxygen (O2) Burning fossil fuels Nitrogen (N) in fossil fuel Fig. 18-9, p. 477

  40. Global Outlook: Photochemical Smog in Santiago, Chile

  41. Several Factors Can Decrease or Increase Outdoor Air Pollution (1) • Outdoor air pollution may be decreased by • Settling of particles due to gravity • Rain and snow • Salty sea spray from the ocean • Winds • Chemical reactions

  42. Several Factors Can Decrease or Increase Outdoor Air Pollution (2) • Outdoor air pollution may be increased by • Urban buildings • Hills and mountains • High temperatures • Emissions of VOCs from certain trees and plants • Grasshopper effect • Temperature inversions

  43. A Temperature Inversion

  44. Descending warm air mass Warmer air Inversion layer Inversion layer Sea breeze Increasing altitude Decreasing temperature Fig. 18-11, p. 478

  45. Animation: Formation of photochemical smog

  46. Animation: Thermal inversion and smog

  47. 18-3 What Is Acid Deposition and Why Is It a Problem? • Concept 18-3 Acid deposition is caused mainly by coal-burning power plant and motor vehicle emissions, and in some regions, threatens human health, aquatic life and ecosystems, forests, and human-built structures.

  48. Acid Disposition Is a Serious Regional Air Pollution Problem • Acid deposition, acid rain • Formation • Local versus regional problems • Effects of prevailing winds • Buffers • Where is the worst acid deposition?

  49. Natural Capital Degradation: Acid Deposition, Acid Rain

  50. 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 depostion (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. 18-12, p. 479

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