LOUISVILLE, Ky. (AP) — Clean air advocates on Thursday criticized a decision by the Obama administration to scrap a proposed smog regulation because of the ailing economy, saying the stricter rule would create thousands of jobs in Kentucky and Tennessee.

The federal Clean Air Act has encouraged technological advancement and economic growth since it was enacted in the 1970s, said Mary Gade, an environmental consultant.

"The naysayers want to tell you these air pollution measures are job-killing," said Gade, former chief of the Environmental Protection Agency's regional office in Chicago. "To the contrary, they're job-creating and they help us transform this economy into a green economy in which we can look at new sources of electric power that are cleaner and safer."

Gade, representatives from the American Lung Association and others spoke to reporters on Thursday in a conference call about air quality in the two states.

Last week the Obama administration declined to adopt a proposed EPA regulation aimed at reducing smog in an effort to lighten regulatory burdens on business in a weak economy. The regulation would have reduced concentrations of ground-level ozone, the main ingredient in smog.

Republican lawmakers, urged on by business leaders who said compliance with tougher regulations would be costly and hamper job growth, had pledged to try to block the stricter smog standards as well as other EPA regulations. The EPA had predicted the proposed smog change would cost up to $90 billion a year, making it one of the most expensive environmental regulations ever imposed in the U.S.

But Gade pointed to a study this year by the University of Massachusetts that said proposed changes to the government's air pollution rules would create 113,000 jobs in Tennessee and 31,000 jobs in Kentucky over five years. The jobs would arise from investment in pollution controls and new energy generation, and would offset any job losses from coal-fired power plant closures, the study said.

Betsy Janes with the American Lung Association of Kentucky said Midwestern the coal-burning plants have a powerful effect on air quality in Kentucky and Tennessee. She said the association's annual "State of the Air" report ranked Louisville 10th and Knoxville 24th on a list of cities with the highest year-round particle pollution.

The American Lung Association, which had sued the EPA over smog standards under former President Bush, said it would resume its legal fight in response to Obama's decision to pass on imposing stricter limits. The group had suspended its lawsuit after the Obama administration pledged to change it.