Adverse cardiopulmonary and respiratory health effects and the number of premature deaths could be significantly reduced if the current US ambient air quality standards for ozone were lowered, according to research.
Establishing a more stringent ozone standard in the US would significantly reduce ozone-related premature mortality and morbidity, according to a study published July 18 online ahead of print by the journal Environmental Health Perspectives.
“Abundant evidence links exposure to ozone with adverse health effects, including impaired pulmonary function, asthma exacerbations, increased hospital and emergency room visits, and increased mortality, yet the current National Ambient Air Quality Standard of 75 ppb [parts per billion] is often exceeded,” said lead author Jesse Berman, PhDc, from Johns Hopkins Bloomberg School of Public Health, Baltimore.
“Our study shows that adhering to the current standard [which was put in place in 2008] 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.” The research was supported in part by an American Thoracic Society research contract.
Using national ozone monitoring data for 2005-2007 and concentration-response data obtained or derived from the epidemiological literature, Berman and colleagues applied health impact assessment methodology using the Environmental Benefits Mapping and Analysis Program (BenMAP) to estimate the numbers of deaths and other adverse health outcomes that would have been avoided during this time period if the current eight-hour average ozone standard (75 ppb) or lower standards had been met.
The researchers estimated that if the current ozone standard of 75 ppb had been met, 1,410 to 2,480 ozone-related premature deaths would have been avoided during the study period. At a lower standard of 70 ppb, 2,450 to 4,130 deaths would have been avoided, and at a standard of 60 ppb, 5,210 to 7,990 deaths would have been avoided. At the 75 ppb standard, acute respiratory symptoms would have been reduced by three million cases and school-loss days by one million cases annually. Even greater avoided mortalities and morbidities would have been achieved at 70 ppb and 60 ppb standards.
“The EPA’s Clean Air Scientific Advisory Committee has recommended adoption of an ozone standard in the 60 to 70 ppb range,” Berman said. “Our analysis shows that implementing such a lower standard would result in substantial public health benefits.”
Berman JD, Fann N, Hollingsworth JW, et al. Health benefits from large-scale ozone reduction in the United States. Environ Health Perspect. 2012 Jul 18; [Epub ahead of print].