WASHINGTON — The Environmental Protection Agency on Thursday proposed limiting the allowable amount of pollution-forming ozone in the air from 75 to between 60 and 70 parts per billion for any eight-hour period, significantly tightening rules the Bush administration had set for the nation's most widespread air pollutant.
The final target that the Obama administration adopts will have huge implications for the regulations state and local officials will have to set in the coming months to meet the new federal requirements. Power plants and motor vehicles are significant emitters of pollutants such as nitrogen oxides and other chemical compounds that form ozone when exposed to sunlight.
Smog exposure is linked to an array of heart and respiratory illnesses. It causes burning and inflammation in sensitive tissues and can harm wilderness areas and farm crops by stunting the growth of trees and plants.
Depending on the level of the final standard, the EPA estimates the proposal will cost between $19 billion and $90 billion to implement and will yield health benefits of between $13 billion and $100 billion.
The proposal would translate into thousands of avoided premature deaths by 2020, though the exact number depends on what exact limit the agency adopts.
Clean Air Watch president Frank O'Donnell called ozone "one of the most dangerous" pollutants in the country. "Smog can, and does, kill. This action will literally save lives and mean better health protection from coast to coast."
Ozone standards have been the center of a political and legal battle since the spring of 2008, when the EPA set a looser limit than what its own scientific advisers had suggested and President Bush himself intervened to scale back the agency's proposal at the last minute. The new proposal mirrors what EPA's Clean Air Scientific Advisory Committee unanimously recommended in 2007.