Air Pollution a Problem in California?


Why is air pollution a problem in California?
Three main factors are behind the unhealthy levels of air pollution in California:

  1. Large amounts of air pollution are generated by the activities of 33 million people,
  2. Terrain or topography traps pollution, and
  3. A warm, sunny climate helps form ozone and other air pollutants.

Lots of People, Lots of Pollution
During personal and business activities, Californians release thousands of tons of pollutants into the air every day. Although each of us may only produce a small amount of air pollution, the combined pollution from the 33 million Californians adds up to a big problem.

Sources of Air Pollution
Some air pollutants are formed and released during the combustion (burning) of petroleum-based products and other fuels such as wood. Examples of these air pollution sourcesare:

  • Gasoline and diesel-powered motor vehicles such as cars, trucks, trains and boats;
  • Factories;
  • Power plants; and
  • Fireplaces.

Many tons of pollutants also enter the air through evaporation (liquids turning into gases). Sources of air pollution from evaporation include:

  • Fuel from gasoline storage and dispensing facilities (service stations, gasoline terminals, and refineries);
  • Car and truck gasoline tanks and gasoline storage containers;
  • Businesses that use solvents and paint;
  • Personal, household, and commercial consumer products such as hairsprays, automotive cleaning products, and aerosol paints that contain smog-forming ingredients such as hydrocarbon propellants and alcohol.

A Perfect Place for Smog
California's topography (the physical shape of the land) and its warm, sunny climate are perfect for trapping and forming air pollutants. Most California cities are built on plains or in valleys surrounded by mountains. These areas are natural bowls that trap air pollution and prevent the air from circulating. On some days temperature inversions (where the air closer to the ground becomes cooler than the air above) act as lids which trap air pollutants close to the ground. This prevents vertical mixing (the upper, cleaner air mixing with the lower, polluted air) and the dispersion of pollutants.

On hot, sunny days, pollutants emitted by vehicles, industry, and many products (nitrogen oxides and volatile organic compounds) react with each other to form ozone, the main ingredient of smog.

During the winter, temperature inversions can trap tiny particles of smoke and exhaust from cars, trucks, fireplaces, and anything else that burns fuel. This keeps the pollution close to the ground - right where people are breathing.

For more suggestions, check out Whatcha Doin' About Air Pollution
and 50 Things You Can Do for Cleaner Air.