Air pollution below EPA standards linked with higher death rates

A new study by 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.

“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,” said senior author Joel Schwartz. “This study shows that it is not enough. We 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.”

Previous studies have linked both short- and long-term exposure to PM2.5 with increased mortality, through mechanisms such as heart disorders, increased blood pressure, and reduced lung function.

They found that both short- and long-term PM2.5 exposure was significantly associated with higher death rates, with annual exposures below EPA standards. Short-term (two-day) exposure led to a 2.14% increase in mortality per 10 μg/m3 increase in PM2.5 concentration, and long-term (one-year) exposure led to a 7.52% increase in mortality for each 10 µg/m3 increase.

“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,” said Schwartz. “We 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.”

Source: Science daily

N.H.Khider