MSHA announced that approximately 99 percent of the respirable coal mine dust samples collected from April 1, 2016, through June 30, 2016, were in compliance with the agency’s coal mine dust standards. In 2014, the department published a final rule that closed many loopholes in the dust-sampling program that had left miners exposed to the unhealthy dust. The landmark rule also included requirements for more frequent sampling of the mine air and use of a new sampling device and other reforms.

For the recent sampling, the agency analyzed more than 20,000 underground coal mine operator samples using the new, cutting edge Continuous Personal Dust Monitor that provides miners with dust results in real time during the working shift. About 99 percent were in compliance. These results correspond to the respirable dust samples collected from Aug. 1, 2014, through Jan. 2016, during Phase I, when 87,000 dust samples were collected from surface and underground coal mines by MSHA and coal mine operators. Nearly 99 percent of those samples met the dust concentration limit.

Phase III of the rule begins Aug. 1, 2016, and will lower the current respirable dust level of 2.0 mg per cubic meter to 1.5 mg per cubic meter of air. MSHA’s analysis of the sampling results from Phase I found that more than 97 percent of the samples collected would have met compliance at the lower level. The results from Phase II show that more than 98 percent would have been in compliance at the lower level.

Prolonged exposure to respirable coal mine dust causes lung diseases, such as coal workers’ pneumoconiosis, emphysema and progressive massive fibrosis. Collectively known as black lung, these diseases can lead to permanent disability and death. The National Institute for Occupational Safety and Health estimates the disease caused or contributed to the death of more than 76,000 miners.