Stronger Ozone Standards Could Save Lives and Reduce Illness

Tougher standards that set lower tropospheric ozone levels in the U.S. could significantly reduce ozone-related deaths and illness, according to a study led by researchers at the Johns Hopkins Bloomberg School of Public Health. The study is available online in advance of publication in Environmental Health Perspectives.

The National Ambient Air Quality Standard for ozone in the U.S. is 75ppb (parts per billion) for the daily 8-hr maximum. However, the researchers note that the current standard is often exceeded. Exposure to ozone is linked to adverse health effects, including impaired pulmonary function, asthma exacerbations, increased hospital and emergency room visits, and increased mortality.

"Our study shows that adhering to the current standard would result in a significant reduction in morbidity and mortality and, furthermore, that applying even more stringent ozone standards would result in even greater reductions,” said Jesse Berman, lead author of the study and PhD candidate with the Bloomberg School’s Department of Environmental Health Sciences.

Berman and colleagues conducted their analysis using national ozone monitoring data for 2005 to 2007 and concentration-response data obtained or derived from the epidemiological literature. Using the Environmental Benefits Mapping and Analysis Program (BenMAP), they estimated the numbers of deaths and other adverse health outcomes that would have been avoided during this time period if the current eight-hour 75ppb standard or lower standards had been met.

Estimates showed that nationally between 1,410 and 2,480 ozone-related premature deaths could have been avoided during the study period if the current ozone standard of 75ppb had been met. The number of lives potentially saved increases to 2,450 to 4,130 at 70ppb, and between 5,210 and 7,990 at 60ppb. At the 75ppb standard, acute respiratory symptoms would have been reduced by 3 million cases and school-loss days by 1 million cases annually.

“Ozone exposure is not uniform across the country or across years.  As a result, the impact of not complying with the ozone standard is different depending on where you live.  We concluded, for example, that the most avoidable deaths associated with ozone compliance or reduction would occur in New York and Los Angeles,” said senior author, Frank Curriero, PhD, MA, associate professor in the department of Environmental Health Sciences and department of Biostatistics at the Bloomberg School of Public Health.

 Authors of “Health Benefits from Large Scale Ozone Reductions in the United States” are Jesse D. Berman, Neal Fann, John W. Hollingsworth, Kent E. Pinkerton, William N. Rom, Anthony M. Szema, Patrick N. Breysse, Ronald H. White, Frank C. Curriero.

 The research was supported by grants from the NIOSH Education and Research Center for Occupational Safety and Health, the Environmental Protection Agency, the National Institute for Environmental Health Sciences and the American Thoracic Society.

Media contact: Tim Parsons, director of Public Affairs, at 410-955-7619 or tmparson@jhsph.edu.