It's been nearly two months since the federal Government Accountability Office issued a major report that supported the U.S. Mine Safety and Health Administration's proposal to toughen coal dust limits to fight a resurgence of black lung.

That GAO report's findings ended a block by congressional Republicans on issuance of the final MSHA rule, which was proposed two years ago, in October 2010.

In an interview published this week in the United Mine Workers Journal, MSHA chief Joe Main indicated that his agency had completed work on a final version of the rule.

"We have finalized our work here," Main told the Journal. "It's moving through the next level, but that does take some time."

Government records indicate that the black lung rule has not yet reached the White House Office of Management and Budget, which must review it before a final version can be issued. Such a rule would typically go to the Labor Department, MSHA's parent agency, before being sent to the White House for final review.

During a brief interview Wednesday in Charleston, Main declined to provide any specifics about the status of the rule.

"It's going through the process," Main said. "It's still in the process."

Main, a former union safety director, said he had not seen the UMW Journal article and, therefore, would not comment on it. Asked when the administration plans to issue a final rule, and if it would act before next month's general election, Main said, "I don't know when we'll see it."

Black lung, or coal workers' pneumoconiosis, is an irreversible and potentially deadly disease caused by exposure to coal dust.

In 1969, Congress made eliminating black lung a national goal with a law that required mine operators to take steps to limit exposure. The law greatly reduced black lung among the nation's coal miners.

Scientists have found, though, that black lung is on the rise again. Researchers have warned of a doubling of black lung rates since 1997, and of an alarming incidence of the disease among younger miners, whose entire careers took place under the 1969 law's dust limits.

In West Virginia, more than 2,000 coal miners died of black lung between 1995 and 2004, second only to Pennsylvania, with 4,234 black lung deaths during the same period, according to government data. Nationwide, black lung killed more than 10,000 miners during those years.

A joint investigation by National Public Radio and The Center for Public Integrity reported in July on the resurgence of black lung and, with additional reporting by The Charleston Gazette, documented widespread cheating by mining companies on dust samples and inaction by federal regulators over the past quarter-century to address the problem.

Two years ago, MSHA proposed new rules based on such recommendations. Among other steps, the MSHA proposal issued in October 2010, would reduce the legal limit for dust in underground mines from 2.0 milligrams of dust per cubic meter of air to 1.0 milligram of dust per cubic meter of air. A Labor Department advisory commission recommended the change in 1996, and the National Institute for Occupational Safety and Health has been urging since 1995 that the limit be tightened. Industry officials argue that recent increases in black lung rates are a regional problem and don't require a new nationwide rule.

More than a decade ago, Main was the UMW director of safety when the Clinton administration announced its plan to end black lung. Main said the Clinton proposal didn't go far enough, and urged MSHA to scrap it and start over.

The United Mine Workers union's opposition came in late 2000, as the Clinton White House was winding down, scrambling to decide which -- if any -- new initiatives to try to finish up before leaving office. Union resistance was enough to kill the black lung plan.

This time around, UMW officials have objected to portions of the Obama administration's MSHA proposal, but spokesman Phil Smith said this week that the union wants the agency to move forward with a rule.

"We would hope that the rule would be put in place and enforced as soon as possible," Smith said. "It seems like it's been long enough. If they're worried about Republicans calling this another job-killing regulation, let's remember that coal miners are still dying from black lung."

Reach Ken Ward Jr. at kw...@wvgazette.com or 304-348-1702.