Anew federal rule has been shown to have had a significant impact on coal miners'exposure to "dangerous levels of coal mine dust," according to theU.S. Department of Labor's Mine Safety and Health Administration.

In aJuly 18 release, the agency stated that approximately 99% of respirable coalmine dust samples collected during the second quarter of this year were incompliance with MSHA coal dust standards.

Thefirst two phases of the rule have been implemented, with the third and finalphase scheduled to be implemented in August.

"Thesepositive results are due to the extraordinary efforts of MSHA and industryworking to clean up the air that miners breathe and successfully implement thecritical respirable dust rule to protect miners from a disease that has claimedtens of thousands of lives," said Joseph Main, assistant secretary oflabor for mine safety and health. "The nation's coal miners are betterprotected from debilitating and deadly black lung disease than ever before, butwe still have much more work to do to prevent black lung so that miners canspend a career as a miner and not fear the disease."

Accordingto MSHA, the rule is intended to reduce exposure to respirable coal mine dustcausing lung diseases, such as coal workers' pneumoconiosis, emphysema andprogressive massive fibrosis, collectively known as black lung.

Withthe second phase in place, the agency based its results on more than 20,000underground coal mine operator samples using the new, cutting edge ContinuousPersonal Dust Monitor.

Duringthat period, MSHA temporarilydelayed its own dust sampling amid concerns about the functionality of itproximity detection systems and respirable dust sampling devices.

The rule was the subject of industry challenges in 2014; however, theU.S. Court of Appeals for the 11th Circuit denied a legal appeal to reconsider the rule earlierthis year.

Industry advocates, including the National MiningAssociation and Murray EnergyCorp. argued that the second phase of the rule would "cripple"the country's coal sector. According to a Murray spokesman, the companydeclined to appeal the decision.