"America's air is cleaner today than it was a generation ago. By meeting the requirement of the Clean Air Act and strengthening the national standard for ozone, EPA is keeping our clean air progress moving forward," said EPA Administrator Stephen L. Johnson.

The new primary 8-hour standard is 0.075 parts per million (ppm) and the new secondary standard is set at a form and level identical to the primary standard. According to the Washington Post, EPA Staff recommended a secondary standard, which was rejected by the President. The previous primary and secondary standards were identical 8-hour standards, set at 0.08 ppm. Because ozone is measured out to three decimal places, the standard effectively became 0.084 ppm, and areas with ozone levels as high as 0.084 ppm were considered as meeting the 0.08 ppm standard, because of rounding.

Pennsylvania Department of Environmental Protection Secretary Kathleen A. McGinty said that the new ground level ozone standards ignore the recommendations of the agency's own Clean Air Scientific Advisory Committee, and consequently, do not go far enough in protecting human health and the environment. Pennsylvania has urged the EPA to adopt the committee's recommendations in setting the new acceptable levels for ozone. "I am disappointed the EPA administrator ignored the advice of his own scientific advisory committee in setting the new ozone level that is intended to protect people's health," said McGinty. "Sound science must be used in setting public policy, and that has not happened in this case. Unfortunately, this action is in keeping with the EPA's track record of ignoring science and making decisions based on politics."

The EPA's Clean Air Scientific Advisory Committee, which includes members from academia and private research institutions, recommended the standard be set between 60 and 70 ppb of ozone in order to protect human health. The federal agency today set the standard above that recommendation at 75 ppb. "Last fall, the commonwealth offered testimony before the EPA that the decision on new ozone standards should be based on scientific advisory committee’s recommendations," said McGinty. “The federal Clean Air Act is clear that protecting the public's health must be the driving force in setting primary standards, but EPA has not adhered to that requirement." Pennsylvania and other states must monitor the air for ozone and other pollutants, and take steps to meet the EPA-set standards. Air containing ozone measured at 84 ppb meets the present standard.

EPA Administrator Johnson said, "The Clean Air Act is not a relic to be displayed in the Smithsonian, but a living document that must be modernized to continue realizing results. So while the standards I signed may be strict, we have a responsibility to overhaul and enhance the Clean Air Act to ensure it translates from paper promises into cleaner air." Ozone can harm people's lungs, and EPA is particularly concerned about 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.

Ground-level ozone is not emitted directly into the air, but 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.

EPA estimates that the final standards will yield health benefits valued between $2 billion and $19 billion. Those benefits include preventing cases of bronchitis, aggravated asthma, hospital and emergency room visits, nonfatal heart attacks and premature death, among others. EPA's Regulatory Impact analysis shows that benefits are likely greater than the cost of implementing the standards. Cost estimates range from $7.6 billion to $8.5 billion.

EPA selected the levels for the final standards after reviewing more than 1,700 peer-reviewed scientific studies about the effects of ozone on public health and welfare, and after considering advice from the agency's external scientific advisors and staff, along with public comment. EPA held five public hearings and received nearly 90,000 written comments.

As part of this action, EPA also has updated the Air Quality Index (AQI) for ozone to reflect the change in the health standard. The AQI is EPA's color-coded tool for communicating daily air quality to the public. (Env. Tip of the Week-3/17/08)