EPA Administrator Stephen Johnson unveiled plans Dec. 21 to reduce the 24-hour fine particle standard from the current level of 65 micrograms per cubic meter to 35 micrograms. Environmental regulators track fine particle pollution at monitoring stations in metropolitan areas throughout the country.

Fine particle pollution, much of which comes from automobile exhaust and power plant emissions, has been linked to asthma, heart problems and early death.

The EPA said it will collect public comments on its proposal for 90 days and finalize a standard by Sept. 27, 2006.

Environmental and health groups including the American Lung Association and Clean Air Watch have criticized the proposal as not doing enough to protect public health, saying the reductions are less than the reductions the EPA´s own staff recommended in June after analyzing health studies.

"It was clear to the American Lung Association, to EPA´s own staff scientists and to the independent scientific review panel that much tighter limits were needed," ALA President John Kirkwood said.

However, Scott Segal, director of the Electric Reliability Coordinating Council, which represents electric utilities, said the new standards are premature and ignore other studies that suggest particle pollution is not as dangerous as originally thought.

"It is hard to see the justification for ratcheting the national PM standard lower at this point," Segal said, adding that increased costs to electric generators needing to reduce emissions could hurt the poor as the costs are passed along.

EPA Administrator Johnson said the agency´s decision was based on the best available science. He also said the science is complex and that informed individuals could reach different conclusions, which is why the EPA is anxious to consider public comments.

Details about the proposal and how to submit comments are available online at www.epa.gov/air/particles.