Air pollution below EPA limits too can cause death

Washington: A new study has linked air pollution below EPA standards with higher death rates.

Researchers at Harvard T.H. Chan School of Public Health found that death rates among people over 65 are higher in zip codes with more fine particulate air pollution (PM2.5) than in those with lower levels of PM2.5.

It is the first study to examine the effect of soot particles in the air in the entire population of a region, including rural areas. The harmful effects from the particles were observed even in areas where concentrations were less than a third of the current standard set by the Environmental Protection Agency (EPA).

Senior author Joel Schwartz said that most of the country is either meeting the EPA standards now or is expected to meet them in a few years as new power plant controls kick in, but this study shows that it is not enough.

He added that people need to go after coal plants that still aren't using scrubbers to clean their emissions, as well as other sources of particles like traffic and wood smoke.

Researchers found that both short- and long-term PM2.5 exposure was significantly associated with higher death rates, even when restricted to zip codes and times with annual exposures below EPA standards.

Particulate air pollution is like lead pollution, there is no evidence of a safe threshold even at levels far below current standards, including in the rural areas we investigated, noted Schwartz, adding they need to focus on strategies that lower exposure everywhere and all the time and not just in locations or on days with high particulate levels.

The study appears online in Environmental Health Perspectives.