Harmful effects from soot particles were observed even in areas where concentrations were less than a third of the current standard set by the 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.
Source-ANI