Missouri State University

Sustainability at Missouri State

Ozone

What is Ozone?

Ozone (O3) is a gas composed of three oxygen atoms. It is not usually emitted directly into the air, but at ground-level is created by a chemical reaction between oxides of nitrogen (NOx) and volatile organic compounds (VOC) in the presence of sunlight. Ozone has the same chemical structure whether it occurs miles above the earth or at ground-level and can be "good" or "bad," depending on its location in the atmosphere.

Stratospheric Ozone

The stratosphere, or "good" ozone layer extends upward from about 6 to 30 miles and protects life on Earth from the sun's harmful ultraviolet (UV) rays. This natural shield has been gradually depleted by man-made chemicals like chlorofluorocarbons (CFCs). A depleted ozone shield allows more UV radiation to reach the ground, leading to more cases of skin cancer, cataracts, and other health and environmental problems.

Ground-level Ozone

In the earth's lower atmosphere, ground-level ozone is considered "bad." Motor vehicle exhaust and industrial emissions, gasoline vapors, and chemical solvents as well as natural sources emit NOx and VOC that help form ozone. Ground-level ozone is the primary constituent of smog. Sunlight and hot weather cause ground-level ozone to form in harmful concentrations in the air. As a result, it is known as a summertime air pollutant. Many urban areas tend to have high levels of "bad" ozone, but even rural areas are also subject to increased ozone levels because wind carries ozone and pollutants that form it hundreds of miles away from their original sources.

Why You Should Care

The EPA has recently lowered the level of permissible ozone in the air from 80 parts-per-billion (ppb) to 75 ppb. That means that for every billion molecules of air, no more than 75 can be ozone molecules. Before, Springfield was well below the required 80 ppb level of ozone and there was little concern that we would be any regulatory action taken. Now, however, we are much closer to exceeding the new, lower standard. As Springfield and the surrounding areas expand and grow, it is more likely that we will exceed 75 ppb of ozone.

If we act now, we can reduce ozone levels and be compliant with EPA standards. By making voluntary changes, we may be able to avoid mandatory ones.

How Can You Help? 

Local businesses, governments and other organizations can help reduce ozone pollution by taking a variety of voluntary actions. These actions could help the area improve air quality and avoid costly mandatory requirements should our air quality status change to "non-attainment". These actions can also help your organization save money and improve employee well-being.

Ground-level Ozone Reduction Tips

  • Reduce vehicle emissions by carpooling or riding the bus. City Utilities reduces bus fares to $0.50 on Ozone Alert Days.
  • Work from home (telecommute) if your employer offers such programs
  • Put-off mowing your lawn. Air emissions from running an average gas-powered lawn mower for 1 hour is the equivalent of driving your car 200 miles. Simply mow your lawn during the evening hours of a non-alert day.
  • Reduce vehicle and equipment idling.
  • When it's time to replace your car or truck, consider purchasing a more fuel-efficient vehicle such as: gas-electric hybrids, diesel-electric hybrids, biodiesel, or compressed natural gas.

Other suggestions for both individuals and companies are available on the Ozarks Clean Air Alliance: Ozarks Ozone Network page.