The Fight over Particulate Matter

The EPA and conventional air pollution regulations are back in the news. NPRreported that the seven-member Clean Air Scientific Advisory Committee (CASAC), which provides the EPA with technical advice for National Ambient Air Quality Standards, is “considering guidelines that upend basic air pollution science.” But NPR’s oversimplified depiction of a settled scientific debate ignores real misgivings about the science that has justified the regulations and provides an opportunity to ask questions about the proper role of science in publi c policy.The pollutant in question is particulate matter (PM), tiny particles or droplets emitted from power plants, factories, and cars. The EPAcontends that PM with diameters smaller than 2.5 micrometers, about 3 percent of the size of a human hair, is the most harmful because the particles can be inhaled deep into the lungs. Along withfive other criteria pollutants, the Clean Air Actrequires that the EPA periodically prepare an analysis that “accurately reflects the latest scientific knowledge” on the health effects of PM exposure. It must then set air quality standards “requisite to protect the public health…allowing an adequate margin of safety.”Whether one favors leaning towards caution and setting stringent pollutant standards or is skeptical of the efficacy of air quality rules and worries about the costs of the regulations, PM is important. On the one hand, the supposed harms of PM are high. One (contested)study claime...
Source: Cato-at-liberty - Category: American Health Authors: Source Type: blogs