Exposure to low levels of air pollution can increase mortality rates, study says

Exposure to low levels of air pollution can increase mortality rates, says a study by researchers published in Environmental Health Perspectives. "The Environmental Protection Agency rates air pollution based on concentrations of particles smaller than 2.5 microns, or PM2.5," Nicholas Bakalar reports for The New York Times. "It generally regards as safe an annual average of 12 micrograms per cubic meter of air or 35 micrograms per cubic meter over a one-day period."

The study, which tracked short-term and long-term air pollution exposure of 550,000 Medicare recipients 65 and older in New England from 2003 to 2008, found that "each 10 microgram per cubic meter increase in PM2.5 was associated with a 2.14 percent increase in death rate over a two-day period and a 7.52 percent increase over a year," Bakalar writes. "Even in rural areas like northern Maine where the EPA standard was consistently met, the results were similar. For each 10 microgram increase, there was a 2.14 percent higher death rate short-term and 9.28 percent higher over a full year."