New Particulate Rules Are Anything But Fine, Say Scientists.

The article informs that critics of revision to air pollution standards, proposed last month by the U.S. Environmental Protection Agency (EPA), say the new daily threshold will only marginally improve public health. In fact, an outside panel that made such a recommendation is not happy with EPA's decision. EPA Administrator Stephen Johnson did not answer that question during a 20 December teleconference announcing the standards but said he had thought long and hard about the data. Studies have shown that inhaling the small particles that make up soot, a widespread byproduct of combustion, harms health, although the mechanisms are not all clear. In 1997, the EPA first regulated fine particles measuring 2.5 micrometers or less. As part of a settlement in a suit brought by the American Lung Association, EPA was required to propose revised PM 2.5 rules by the end of 2005. Such a reduction could make a big difference in public health, scientists have found. The EPA models for nine major U.S. cities predict that the tightest daily and annual standards recommended by CASAC would cut the roughly 4700 deaths due each year to PM 2.5 in those cities by 48%.