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.
The Tulsa area was designated an attainment area for ozone in 1990 after 20 years of non-attainment designation. Only a year later the area began again to exceeded the ozone standard. This led to the development of the INCOG Air Quality Committee and the Tulsa Area OZONE ALERT! program was designed and implemented. The goal of the program was to maintain Tulsa's attainment status for ozone thereby ensuring healthy air.
And it still is today! The OZONE ALERT! program takes a voluntary, episodic approach to ground-level ozone pollution reduction. 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, Text Alerts, automated widgets, media and numerous various other communications methods. Governments, businesses, industries and individuals are urged to take voluntary action to reduce emissions that form ground-level ozone on Ozone Alert! days.
The Clean Air Act gives the EPA authority to establish national ambient air quality standards (NAAQS). Of the six pollutants, only ozone continues to challenge the Tulsa area. Although the EPA has lowered the ozone standard three times since 1990, as of now, the Tulsa area and the state of Oklahoma remain in attainment of the NAAQS (not on the EPA's 'Dirty Air List').
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 OzoneAlert.com 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 70 parts per billion (ppb).
Areas not meeting the standard are not automatically designated non-attainment. Violating the standard, rather, initiates an official and lengthy course of action including but not limited to determining nonattainment area boundaries and assessing emission reduction strategies to regain compliance. The nonattainment designation often occurs three or more years after the area first violates a national standard.
Local, national and even international TV meteorologists report an Air Quality Index (AQI). This index provides an easy-to-understand way to explain the quality of the air. An AQI of 100 and below 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 - an unhealthy air day.
Ozone exposure may lead to
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 EPA estimates that 5 to 20 percent of the total U.S. population has a susceptibility to the harmful effects of ozone air pollution.
Click here to view a glossary of ozone and pollution-related terms.