December 2014

Last week, the Environmental Protection Agency issued a proposed rule to revise the National Ambient Air Quality Standard for ozone. EPA is proposing to change the current standard of 75 ppb/8-hours to a stricter standard in the range of 65-70 ppb.

While the ATS is pleased EPA is proposing a stricter standard, the society is concerned EPA is not considering a standard of 60 ppb. "The body of scientific evidence supporting the health benefits of a lower ozone standard has grown substantially in the last few years," said John R. Balmes, MD, a pulmonary critical care physician and chair of the ATS Environmental Health Policy Committee. "Ozone pollution has been linked to low birth weight, decreased lung function and other respiratory problems in infants and children, worse asthma control in both children and adults, and with cardiovascular disease and increased mortality in adults."

"While some evidence shows that ozone exposure below 0.060 ppm also has adverse health effects, the strongest data support the connection between exposure at levels above 0.060 ppm and serious adverse health effects in people of all ages."

The recent evidence linking ozone pollution and adverse health effects includes studies showing dose-response relationships between ozone exposure and hospital admissions for asthma in children and hospital admissions for asthma and COPD in adults, lung function deficits in healthy adults exposed to ozone at levels between 0.060 and 0.070 ppm, and an increased mortality risk associated with ozone exposure, primarily affecting the elderly and patients with chronic diseases.

EPA's proposed rule is now open for public comment. By court order, the final ozone rule will be issued in September of 2015.