Study links soot levels below EPA standards to higher death rate

摘要

A Harvard University study published yesterday links airborne soot to higher death rates in people over age 65, even at pollution concentrations below federal standards. Researchers said their study was the first to examine how fine particulate matter (PM2.5) affects a broad population, including people in rural areas. Fine particles are about onethirtieth the width of human hair. Their results, they said, point to a need for further reducing fine particulate pollution. The study, they added, also shows that improving air quality beyond U.S. EPA standards that were last revised in 2012 could benefit public health.