WASHINGTON >> Responding to a lawsuit from 11 states, the Environmental Protection Agency is proposing new air quality standards to lower the amount of soot that can be released into the air.

The Obama administration, facing strong resistance from congressional Republicans and industry officials, had sought to delay the politically fraught rule until after the election, but was forced to act by a court order. Critics, including officials representing the oil and gas industry, refineries and manufacturers, complained that overly strict rules could hurt economic growth and lead to job losses.

Soot, made up of microscopic particles released from smokestacks, diesel trucks, wood-burning stoves and other sources, contributes to haze and can burrow into lungs. Breathing in soot can cause lung and heart problems.

Dr. Albert Rizzo, chairman of the board of the American Lung Association, said soot, also known as fine particle pollution, is a known killer. “The science is clear, and overwhelming evidence shows that particle pollution at levels currently labeled as officially ‘safe’ causes heart attacks, strokes and asthma attacks,” he said.

The long-delayed rule, to be made public on Friday, responds to a federal court order requiring the Obama administration to update air quality standards under the Clean Air Act. Administration officials described the rule to The Associated Press on condition of anonymity because it has yet to be announced.

Eleven states, including New York and California, filed suit earlier this year to force a decision. The states and the American Lung Association say current standards jeopardize public health. Soot has been linked to thousands of premature deaths each year, as well as aggravation of respiratory illnesses, heart attacks and strokes.

An Obama administration official said the new rule was based on a rigorous scientific review. Virtually all counties in the United States would meet the proposed standard with no additional actions needed beyond compliance with current and proposed rules set by the EPA, the official said.

More than a dozen states, along with environmental groups, sued the EPA several years ago, contending that the Bush administration had ignored science and its own experts when it decided in 2006 not to lower the nearly decade-old annual standard for soot. The agency’s own analysis found a lower standard recommended by scientific advisers would have prevented almost 2,000 premature deaths each year.

The EPA initially promised it would review recent science and issue a decision in 2011. After months of inaction, states led by New York filed suit to force a decision. The lung association and the National Parks Conservation Association filed a similar suit. A federal court eventually ordered the EPA to propose a new rule by Thursday. A final rule is due in December after a public comment period.  

The new rule would set the maximum allowable standard for soot at range of 12 to 13 micrograms per cubic meter of air. The current annual standard is 15 micrograms per cubic meter.

Administration officials said the proposed changes are consistent with advice from independent scientists and are based on extensive research showing negative health impacts from soot at lower levels than previously understood. The agency will solicit comments from the public, as well as industry, public health groups and other interested groups to help determine the final standard.

Besides California and New York, states joining in the lawsuit forcing an EPA decision were Connecticut, Delaware, Maryland, Massachusetts, New Mexico, Oregon, Rhode Island, Vermont and Washington.