Unit 7-3-Controlling Air Pollution

• Explain how the provisions of the Clean Air Act have reduced air pollution in the United States

• Describe international efforts to reduce the ozone hole

The Clean Air Act

• First passed in 1963

• Meant to address air pollution in the United States

  • Takes measures to reduce the emission of pollutants that cause health problems such as asthma and cancer

  • Limits the release of pollutants responsible for smog and acid deposition

• It has been revised several times to set stricter standards for air quality and strengthen the government's ability to enforce regulations

  • The most important revisions occurred in 1970 and 1990

• Handled by the EPA

• Since the Clean Air Act, the release of the worst air pollutants has gone down 57%

Provisions of the Clean Air Act

• Limits emissions of pollutants by motor vehicles and industries

• It sets standards for air quality

  • Limits the concentration of specific pollutants

    • Sets upper limits based on the maximum amount that humans can tolerate

• Lets people sue industries that break the rules

• Sets aside funds for research into pollution control

Reduction in Pollutants from Motor Vehicles

• Catalytic Converters: a device in a motor vehicle that reduces the amount of pollutants in emissions

  • Changes harmful pollutants into less harmful forms

  • Are in all Cars in the United States since 1975

    • Located between the engine and the muffler

• Car Gasoline no longer contains lead

Reduction in Pollutants from Industries and Power Plants

• Industrial Power Plants are required to reduce the amount of pollutants they produce

• Scrubbers: Remove Pollutants or chemically change them before they leave the factory smokestacks

The Ozone Hole

• Ozone is considered a pollutant when it is in the troposphere, but needed in the stratosphere

• During the late twentieth century, amounts of ozone in the stratosphere were lower than they should be

  • By 1985 the amount of ozone had dropped 40-60% over Antarctica

    • The area was Dubbed The Ozone Hole

Chlorofluorocarbons

• In 1974, Sherwood Rowland and Mario Molina identified chemicals that decrease the amounts of Ozone in the atmosphere

• Chlorofluorocarbons (CFCs): A family of chemical compounds containing Chlorine, Fluorine, and Carbon

  • Were used in refrigerators and aerosols

  • Release chlorine atoms into the atmosphere that destroy ozone molecules

The Montreal Protocol

• Concerns over the effects of the ozone layer lead many nations to restrict the production of CFCs and other ozone-depleting substances

• Montreal Protocol (1987): a treaty that called for major cuts in CFC manufacturing

  • Was strengthened by amendments

  • Dropped production of CFCs by 95%

• Over time, the Ozone Hole has started to Recover

  • Considered the biggest success story in international cooperation in response to Environmental Concerns