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Air Quality

Air Quality. Chapter 1, Section 4, p22-25. Air Quality. Pollutants : harmful substances in the air, water, or soil Air containing harmful particles or gases = polluted Air pollution can affect the health of humans and other living things. Sources of Pollution.

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Air Quality

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  1. Air Quality Chapter 1, Section 4, p22-25

  2. Air Quality • Pollutants: harmful substances in the air, water, or soil • Air containing harmful particles or gases = polluted • Air pollution can affect the health of humans and other living things

  3. Sources of Pollution • Some air pollution occurs naturally • Many types of air pollution are the result of human activities

  4. Natural Sources • Natural processes that add particles to the atmosphere • Smoke & dust released into air • Forest fires • Soil erosion • Dust storms • Wind carries mold & pollen articles • Erupting volcanoes release dust clouds, ash, & poisonous gases

  5. Human Activities • Human activities that add pollution to air • Farming & construction sends soil & dust into the air • Burning fossil fuels causes most air pollution • Half from cars & other motor vehicles • Factories & power plants burning coal and oil also release pollution

  6. Fossil Fuels • Burning fossil fuels causes most air pollution • Release particles and gases • Soot enters air when people burn wood or coal • Dark color of smoke from soot • Fossil fuels contain hydrocarbons • Compounds made of hydrogen & carbon • Hydrocarbons don’t burn completely & escape • Pollutants • Carbon monoxide • Nitrogen oxides • Sulfur oxides

  7. Smog & Acid Rain • The burning of fossil fuels can cause smog & acid rain • High levels of air pollution decrease air quality

  8. London-Type Smog • London-type smog forms when particles in coal-smoke combine with water droplets in humid air • Smog = smoke +fog • 1900’s London England dark and dirty • Factories burned coal • Most houses heated by coal • Air full of soot

  9. Photochemical Smog • Photchemical smog: brown haze that develops in sunny cities • Photo means “light” • Formed by sunlight acting on pollutants i.e. hydrocarbons, & nitrogen oxides • Chemicals react to form brownish ozone & other pollutant mixture

  10. Photochemical Smog • Ozone in stratosphere blocks UV radiation – protecting life on Earth • Ozone in troposphere – pollutant • Irritate eyes, throat, & lungs • Harm plants and other living things • Damage many materials

  11. Acid Rain • Acid rain: rain that contains more acid than normal • Rain is naturally, slightly acidic • Forms when nitrogen oxides & sulfur oxides combine with water to form nitric & sulfuric acid • Burning coal with lots of sulfur = sulfur oxides • Rain, sleet, snow, fog, dry particles carry acids to trees & lakes • Damage surface of buildings • Harms lakes & ponds • Makes water acidic • Plants, amphibians, fish, & insects can’t survive

  12. Improving Air Quality • Positives: • Air quality in the US has improved over the last 30 yrs • In the United States, the federal and state governments have passed a number of laws and regulations to reduce air pollution • EPA (Environmental Protection Agency) • Monitors air pollution in the US • Amounts of most major air pollutants have decreased • Newer cars cause less pollution • Newer power plants less polluting than older power plants

  13. Improving Air Quality • Negatives: • Air in many American cities still polluted • More cars on road • More power plants burning fossil fuels

  14. Improving Air Quality • Efforts to reduce air pollution • Voluntary measures – using public transportation more • Stricter regulations needed to control air pollution • Reducing air pollution could be very expensive and benefits might not be worth cost

  15. Pittsburg, 1857

  16. Pittsburg, 1890

  17. Pittsburg, 2010

  18. Mongolia, 2005

  19. China, 2008

  20. Beijing, 2011

  21. Delhi, India

  22. Homework • Read Section 4, p22-25 • Answer ?s 1-3 p25

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