WASHINGTON — President Obama sided with business interests against the Environmental Protection Agency (EPA) on Friday and withdrew a plan to toughen the Bush administration's limits on smog.

The proposed smog rule was a top priority for the EPA and health and environmental groups because dirty air has been shown to contribute to early death, heart attacks and lung problems, including bronchitis and asthma.

It was one of 10 regulations targeted this week for elimination by House Republican leader Eric Cantor, of Virginia, but Obama beat him to it.

The EPA tightened the standard for ozone, the main component in smog, during the Bush administration in 2008. However, the agency's scientific-advisory board unanimously advised that the new standard wasn't strong enough.

Ground-level ozone is formed when emissions from power plants, other industrial facilities, vehicles and landfills react in sunlight.

Obama said in a short written statement that he'd decided against making the smog rule stronger because it would put too big a burden on business in a tough economic time.

His decision was announced shortly after disheartening employment numbers were released.

Republicans said scrapping the smog rule was the right thing to do, but they hammered Obama anyway. Senate GOP leader Mitch McConnell, of Kentucky, said the decision "highlights the devastating impact on jobs that has been created by this administration's regulatory overreach."

Business groups had argued the smog rule would put most of the country out of compliance with pollution standards, and that pollution controls would have been so costly that many companies would have cut jobs.

Supporters of the rule had argued that its health benefits would outweigh its costs and threats of economic harm were exaggerated.

"The White House is siding with corporate polluters over the American people," Natural Resources Defense Council President Frances Beinecke said. "The Clean Air Act clearly requires the Environmental Protection Agency to set protective standards against smog — based on science and the law. The White House now has polluted that process with politics."

The smog rule was particularly contentious because it could halt or delay the permitting of new industrial facilities if local pollution is too severe. Under a 2001 Supreme Court decision, the EPA is not allowed to take costs into account when setting the ozone standards, but the agency said the compliance costs for industry could range from $19 billion to $90 billion a year by 2020, depending on what level is set. It would yield health benefits worth $13 billion to $100 billion, the agency said.

The retreat on the ozone standard is the latest decision Obama has made that appears to be a capitulation to Republicans, sparking growing disenchantment among his base.

In December, he agreed to extend the Bush tax cuts for the wealthiest Americans. In April, he reached a deal to avert a government shutdown by agreeing to GOP demands for budget cuts. In early August, he signed a deal to lift the nation's debt ceiling and avoid a credit default, though the agreement doesn't guarantee that spending cuts will be balanced by tax increases, as he had insisted.

"Many MoveOn members are wondering today how they can ever work for President Obama's re-election or make the case for him to their neighbors, when he does something like this," said Justin Ruben, executive director of the liberal-advocacy group MoveOn.org, which backed Obama in 2008.

Obama said in his statement that the last review of the scientific literature was in 2006, and that work was under way for the next legally required review, in 2013. "Ultimately, I did not support asking state and local governments to begin implementing a new standard that will soon be reconsidered."

The American Lung Association rejected that reasoning.

"For two years the administration dragged its feet by delaying its decision, unnecessarily putting lives at risk," said its president and chief executive officer, Charles Connor. "Its final decision not to enact a more protective ozone health standard is jeopardizing the health of millions of Americans, which is inexcusable."

Ozone inflames human airways and can make breathing difficult.

The 2008 rule put the ozone level at 75 parts per billion. The EPA in January 2010 proposed setting it at 60 to 70 parts per billion, the range recommended by its Clean Air Scientific Advisory Committee. The final rule was never released.

The EPA projected that the range it proposed would have saved 1,500 to 12,000 lives a year. The EPA also said the stricter ozone rule would have prevented thousands of cases of respiratory infections, asthma attacks and cases of bronchitis.

Material from The Washington Post

is included in this report.