Earth Science

Human Impacts on the Earth Environment

Air Quality

Study Tip
Earth Science Concepts dealing with weather explain how wind, mountainous regions, and temperature inversions affect clouds. Think about how these factors can apply to pollution as well.

Pollutants

  • Pollutants may be naturally occurring materials that are larger quantities than normal.
  • They can also be new compounds that humans have produced.

Air Pollution

  • Air pollution started becoming a problem during the Industrial Revolution, when factories burned fossil fuels, such as coal.
  • Toxic materials from burning coal and using automobiles can cause serious lung damage—sometimes, even death.
  • Photochemical smog is made from a chemical reaction between oil emissions and sunshine. It contains many compounds, mostly importantly, ozone.
  • The Clean Air Act passed in 1970, and regulated many pollutants. The air in the United States has become much cleaner as a result.
  • Winds, mountains, and temperature inversions can affect the levels of pollution a region experiences.
  • Pollutants need to be blown, diluted, or transformed into other compounds if people wish to get rid of them.
Study Tip
Earth Science Concepts dealing with weather explain how wind, mountainous regions, and temperature inversions affect clouds. Think about how these factors can apply to pollution as well.
London in December 1952
In London in December 1952, the “Big Smog” killed 4,000 people over five days.
Concept Check
  • What are pollutants?
  • What is photochemical smog?
  • How are pollutants affected by geography and weather?