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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 winter of 2012/2013 has been bad!.

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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 • The winter of 2012/2013 has been bad!

  3. 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.

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

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

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

  7. Trophosphere/stratosphere

  8. 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.

  9. Air Pollution Comes from Natural and Human Sources • Air pollution • Natural sources • Dust blown by wind • Pollutants from wildfires and volcanoes • Volatile organics released by plants • Withdrawing groundwater • Human sources: mostly in industrialized and/or urban areas • Stationary sources • Mobile sources

  10. Case Study: Air Pollution in the Past: The Bad Old Days • Discovery of fire • Middle Ages • Industrial Revolution • London, England • 1850s; 1952: yellow fog; Clean Air Act of 1956 • United States • 1948: Donora, PA; first U.S. air pollution disaster • Donora Death Fog • 1963: New York City • Global problem

  11. Denora Death Fog

  12. 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 • Discuss: How do primary pollutants become secondary pollutants? In ______ words.

  13. What Are the Major Outdoor Air Pollutants? (1) • Carbon oxides • Carbon monoxide (CO) • Carbon dioxide (CO2) • Sources • Human health and environmental impact • Ozone (O3) • Sources • Human and environmental impact • Discuss: Ozone is good/ ozone is bad. In ___ words.

  14. What Are the Major Outdoor Air Pollutants? (2) • Review: Draw the N cycle and the S cycle. Do not look up. • 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

  15. What Are the Major Outdoor Air Pollutants? (3) • Particulates • Suspended particulate matter (SPM) • Fine • Ultrafine • Sources • Human health and environmental impact • Volatile organic compounds (VOCs) • Hydrocarbons andterpenes • Sources • Human and environmental impact

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

  17. Case Study: Lead Is a Highly Toxic Pollutant • Does not break down in the environment • Sources • Human health and environmental impact • Most vulnerable • Reduction of lead (Pb) • Unleaded gasoline • Unleaded paint • Still problems • 2007: toys with Pb paint recalled • Global ban on lead in gasoline and paint

  18. 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

  19. 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

  20. 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

  21. 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

  22. 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.

  23. 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?

  24. Acid Deposition Has a Number of Harmful Effects • Human respiratory disorders • Aquatic ecosystems affected • Release of toxic metals • Leaching of soil nutrients • Loss of crops and trees • Damage to buildings, statues, and monuments

  25. We Know How to Reduce Acid Deposition • Prevention approaches • Clean up • Add lime to neutralize acidified lakes and soil • Add phosphate fertilizer to neutralize acidified lakes

  26. 18-4 What Are the Major Indoor Air Pollution Problems? • Concept 18-4 The most threatening indoor air pollutants are smoke and soot from wood and coal cooking fires (a hazard found mostly in developing countries) and chemicals used in building materials and products.

  27. Indoor Air Pollution Is a Serious Problem (1) • Developing countries • Indoor burning • Poor suffer the greatest risk • Developed countries • Indoor air pollution is greater than outdoor air pollution • Why? • 11 of the common air pollutants higher inside than outside • Greater in vehicles than outside • Health risks magnified: people spend 70–98% of their time is indoors

  28. Indoor Air Pollution Is a Serious Problem (2) • Who are at greatest risk from indoor air pollution? • Children under 5 and the elderly • Sick • Pregnant women • People with respiratory disorders or heart problems • Smokers • Factory workers

  29. Indoor Air Pollution Is a Serious Problem (3) • Four most dangerous indoor air pollutants: • Tobacco smoke • Formaldehyde • Radioactive radon-222 gas • Very small particles • Sources of these pollutants • Human health risks

  30. Indoor Air Pollution Is a Serious Problem (5) • Other possible indoor air pollutants: • Pesticide residue • Pb particles • Living organisms and their excrements • E.g., Dust mites and cockroach droppings • Airborne spores of molds and mildews • Sick-building syndrome

  31. Case Study: Radioactive Radon Gas • Sources • Human health risks • Testing for radon • Correcting a radon problem

  32. 18-5 What Are the Health Effects of Air Pollution? • Concept 18-5 Air pollution can contribute to asthma, chronic bronchitis, emphysema, lung cancer, heart attack, and stroke.

  33. Your Body’s Natural Defenses against Air Pollution Can Be Overwhelmed • Respiratory system protection from air pollutants • Role of cilia, mucus, sneezing, and coughing • Effect of smoking and prolonged air pollution exposure • Chronic bronchitis • Emphysema

  34. Air Pollution Is a Big Killer • 3 Million deaths per year world-wide • Mostly in Asia • Main causes • EPA: proposed stricter emission standards for diesel-powered vehicles • Link between international trade and air pollution • Cargo ships and pollution

  35. Naples, Italy – 2008 Smog from burned trash

  36. 18-6 How Should We Deal with Air Pollution? • Concept 18-6 Legal, economic, and technological tools can help to clean up air pollution, but much greater emphasis should be focused on preventing air pollution.

  37. Laws and Regulations Can Reduce Outdoor Air Pollution • United States • Clean Air Acts: 1970, 1977, and 1990 • EPA • National ambient air quality standards (NAAQs) for 6 outdoor criteria pollutants • National emission standards for 188 hazardous air pollutants (HAPs) • Toxic Release Inventory (TRI)

  38. Laws and Regulations Can Reduce Outdoor Air Pollution • Good news in U.S. • Decrease in emissions • Use of low-sulfur diesel fuel: cuts pollution • Developing countries: more air pollution • What does a scrubber look like?

  39. Case Study: U.S. Air Pollution Can Be Improved • Rely on cleanup more than prevention of pollution • Raise fuel-efficiency for cars, SUVs, and light trucks • Better regulation of emissions of motorcycles and two-cycle gasoline engines • Regulate air pollution for oceangoing ships in American ports

  40. Case Study: U.S. Air Pollution Can Be Improved • Why are airports exempt from many regulations? • Regulate greenhouse gas emissions • Ultrafine particles are not regulated • Urban O3 levels too high • What about indoor air pollution? • Better enforcement of the Clean Air Acts • Is intense pressure needed from citizens to make improvements?

  41. We Can Use the Marketplace to Reduce Outdoor Air Pollution • Emission trading or cap-and-trade program • Mixed reactions to program • SO2 emissions down significantly • NO2 will be tried in the future

  42. There Are Many Ways to Reduce Outdoor Air Pollution • 1980 –2006 • SO2 emissions from U.S. electric power plants decreased by 66% • NOx emissions by 41% • Particulate emissions by 28% • Older plants not governed by the same regulations

  43. Reducing Indoor Air Pollution Should Be a Priority • Greater threat to human health than outdoor pollution • What can be done? • Prevention • Cleanup

  44. We Need to Put More Emphasis on Pollution Prevention • Output approaches • New shift to preventing outdoor and indoor pollution • Pressure from citizens

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