The Obama administration announced a new air pollution standard Friday that would bring about a 20% reduction in microscopic particles of soot emitted by coal-fired power plants and diesel vehicles that contribute to haze and respiratory ailments.

The new limit, fought by industry and welcomed by environmentalists, marks the first time the Environmental Protection Agency tightened the soot standard since it was established 15 years ago.

“These standards are fulfilling the promise of the Clean Air Act,” said EPA Administrator Lisa P. Jackson. “We will save lives and reduce the burden of illness in our communities, and families across the country will benefit from the simple fact of being able to breathe cleaner air.”

Fine particles from burning fossil fuels can penetrate deep into the lungs and lead to heart attacks, acute asthma and premature death, according to the EPA. The new limit that the EPA set for an annual average of airborne fine particles in a given jurisdiction is 12 micrograms per cubic meter, down from 15 micrograms, a standard established in 1997.

The new standard will have a particular impact on California, due to problems from the burning of diesel fuel. According to the EPA’s regional office of the Pacific Southwest, seven California counties may not meet the new standard by 2020: Los Angeles, Riverside, San Bernardino, Imperial, Kern, Merced and Tulare. Still, over the last decade, soot levels have been cut by almost 50% in the Los Angeles area and almost 30% in the San Joaquin Valley, the office said.

via New air pollution standards restrict soot particles – latimes.com.