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 nonattainment.Only a year later the The Ozone season is May-Septarea again began experiencing exceedances of the ozone standard. This led to the development of the INCOG Air Quality Committee which in just two-weeks, developed the OZONE ALERT! program. The first ever voluntary ozone-reduction program of it's kind, the program's goal was to maintain Tulsa's attainment status thereby ensuring healthy air quality for the region.

The OZONE ALERT! program takes a voluntary, episodic approach to reduce the precursor emissions that cause ground-level ozone pollution on the days when reductions are most needed. The Oklahoma Department of Environmental Quality (DEQ), in collaboration with the National Weather Service 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 Text Alerts, E-mail Alert! notices, automated website widgets and many other communication methods. Governments, businesses, industries and individuals are encouraged to take voluntary action to reduce emissions on 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 continues to be ozone. The Tulsa area and the state of Oklahoma remain in attainment (not on the EPA's 'Dirty Air List') of all NAAQS - including ozone.

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 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 of the ozone standard 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 and lengthy course of action must occur. This substantial nonattainment designation process, including the development of a plan with strategic and specific requirements to regain compliance, can take many years and be very costly.

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 8-hr standard. When the AQI is above 100, it is an indication of an exceedance of the air quality standard.

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 can lead to a reduction in lung function, inflammation of the lung lining, and increased respiratory problems. The EPA estimates that 5 to 20 percent of the total U.S. population is effected by 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