All About Ozone

Good Up High, Bad Nearby

Ozone in the upper atmosphere is a beneficial and protective layer around the earth, but ground-level ozone is harmful air pollution that threatens our health, quality of life, and the Tulsa area's economic prosperity. Ground-level ozone is created when sunlight reacts with volatile organic compounds (VOCs) and nitrogen oxides (NOX). Reducing these emissions is necessary to reduce ground-level ozone formation.

Tulsa Program

The Tulsa area was designated an attainment area for ozone in 1990 after 20 years of non-attainment designation. Only a year later the The Ozone season is May-Septarea exceeded the ozone standard. This led the INCOG Air Quality Committee to develop the OZONE ALERT! program. The goal of the program is to maintain Tulsa's attainment status for ozone thereby ensuring healthy air.

The OZONE ALERT! program takes a voluntary, episodic approach to ozone pollution reduction. The Tulsa Branch of the Oklahoma Department of Environmental Quality (DEQ), in collaboration with the National Weather Service and the EPA uses computer modeled predictors to determine when high ozone levels may occur.

OZONE ALERT! days typically occur from May through September on days with high temperatures, minimal cloud cover and light winds. DEQ notifies INCOG and the Tulsa area kicks into Ozone Action. The Alert! word is spread though E-Alert! notices, Fax Alerts, and various other communications methods. Governments, businesses, industries and individuals are urged to take voluntary action to reduce emissions of Ozone Alert! days.

Ozone Standard

The Clean Air Act gives the EPA authority to establish national ambient air quality standards (NAAQS). In the Tulsa metropolitan area, the pollutant of concern is ozone. As of now, the Tulsa area and the state of Oklahoma remain in attainment (not of the EPA's 'Dirty Air List') of the NAAQS

The ozone standard provides increased protection to the public, especially children and other at-risk populations, against a wide range of ozone induced health effects.

The national ozone standard is an 8-hr averaged standard and is calculated by averaging data over a 3-year time period. This average is taken from the 4th highest 8-hour average at each monitoring station. (The homepage shows the location of the five monitoring stations in the Tulsa area.) A violation occurs when the 3-year average of the 4th highest value is greater than .070 parts per million (ppm).

Areas not meeting the standard are not automatically designated non-attainment, rather an official course of action must occur. Specific requirements on how areas will meet the 8-hr standard are developed. All Oklahoma counties are currently in attainment.

Local, national and even international TV meteorologists report an Air Quality Index. This index provides an easy-to-understand way to explain the quality of the air. Anything below a 100 Air Quality Index (AQI) is considered 'healthy' and and AQI above 100 is considered 'unhealthy for certain groups'. The ozone AQI is based on the new 8-hr standard. When the AQI is above 100, it is an indication of an exceedance of the air quality standards.

Health Effects of Ozone

Ozone exposure may lead to

  • Shortness of Breath

  • Chest pain when inhaling deeply

  • Wheezing and Coughing

Long-term, repeated exposure to high levels of ozone may lead to large reductions in lung function, inflammation of the lung lining, and increased respiratory discomfort. The U.S. Environmental Protection Agency estimates that 5 to 20 percent of the total U.S. population has a susceptibility to the harmful effects of ozone air pollution.

Tulsa Area Ozone Trends

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Glossary of Terms

Click here to view a glossary of ozone and pollution-related terms.

Read More

EPA - "Heat, Health & Environment"

NASA Earth Observatory - "The Ozone We Breathe"


EPA "Good Up High, Bad Nearby" Brochure