U.S. mine-safety agency says it will ramp up enforcement of limits on silica; another Labor Dept. unit calls for lower limit

The U.S. Mine Safety and Health Administration says it will inspect underground mines more frequently for silica dust and make them reduce its levels below federal limits while it keeps working on a new standard for silica.

Research has shown that prolonged exposure to silica dust causes pneumoconiosis, or black lung disease. Exposure to silica has increased as thinner coal seams are mined, raising the ratio of silica to coal dust in the process, especially in Central Appalachia.

MSHA said it would make spot inspections at mines with histories of miners being repeatedly overexposed to silica, and if mines have not "timely abated" the hazard, they will be shut down.

“For coal mines, the agency will encourage changes to dust control and ventilation plans to address known health hazards,” MSHA said in a press release. It said it will “focus on sampling during periods of the mining process that present the highest risk of silica exposure for miners.”

"Mine safety advocates want MSHA to cut the amount of silica dust allowed in mines in half, to match what the Occupational Safety and Health Administration allows in other workplaces," notes Curtis Tate of West Virginia Public Broadcasting. The change has been recommended by the Office of Inspector General in the Labor Department, which includes OSHA and MSHA.

"An NPR investigation in 2018 found that exposure to high amounts of silica dust put miners, especially younger ones, at increased risk of developing black lung disease and dying of it," Tate notes.