Clean Air Facts

The fate of Central Oklahoma’s good ozone compliance with federal authorities is seemingly “up in the air” after the Environmental Protection Agency announced its new ozone standard in March 2008. The agency based the changes on the most recent scientific evidence about the health effects of ozone, the primary component of smog.

The new standard will be difficult for the region to meet given that recent historical trends indicate a potential for ozone readings to exceed the new limit set by EPA.

The new primary 8-hour standard is 0.075 parts per million (ppm). The previous standard EPA was set at 0.08 ppm. Because ozone is measured out to three decimal places, the standard effectively became 0.084 ppm: so areas with ozone levels as high as 0.084 ppm, were considered in compliance with the 0.08 ppm standard, because of rounding. The new standard will not allow for mathematical rounding.

In Central Oklahoma, the three-year average of fourth-highest readings at six monitoring sites indicate that five of the stations would violate the new standard if it were in effect today. It only takes one violation at any site to place the entire region in position for a “non-attainment” designation.

The last revision of the ozone standard came in 1997. A requirement of the Clean Air Act forces the agency to periodically review the standard and implement new rules to further improve air quality. EPA estimates that the final standards will yield health benefits. Those benefits include preventing cases of bronchitis, aggravated asthma, hospital and emergency room visits, nonfatal heart attacks and premature death, among others.

Ozone can harm people’s lungs, and is of particularly concern to individuals with asthma or other lung diseases, as well as those who spend a lot of time outside, such as children. Ozone exposure can aggravate asthma, resulting in increased medication use and emergency room visits, and it can increase susceptibility to respiratory infections. EPA estimates that the final standards will yield health benefits that include preventing cases of bronchitis, aggravated asthma, hospital and emergency room visits, nonfatal heart attacks and premature death, among others.

Ground-level ozone forms when emissions of nitrogen oxides (NOx) and volatile organic compounds (VOCs) “cook” in the sun. Power plants, motor vehicle exhaust, industrial facilities, gasoline vapors and chemical solvents are the major human-made sources of these emissions.

Central Oklahomans need to do all they can to help clean our air clean. For health considerations, for our quality of life, and for community pride. There are things that we can do in all facets of our life that can help. These are things that we do at home, at work, as we move, and as we share information with others in our community.