The Obama administration on Thursday proposed to halve the legal limit for miners' exposure to coal dust.
The move is designed to reduce cases of black lung disease, a deadly condition caused by coal dust and other particles found in coal mines. The disease has killed more than 10,000 miners in the last decade alone — and those numbers are on the rise.
The administration's proposal would cut the permissible exposure limit (PEL) for coal dust from 2 milligrams of dust per cubic meter of air — a standard that's been in place since 1972 — to 1 mg/m3.
The new standard would be phased in, with the threshold dropping to 1.7 mg/m3 six months after the final rule is issued; to 1.5 mg/m3 after a year; and to 1 mg/m3 after two years.
The proposal is based largely on findings from the National Institute for Occupational Safety and Health (NIOSH), which issued a comprehensive black lung report in 1995 that recommended lowering the PEL to 1 mg/m3.
Administration officials said Thursday the new rules will go a long way toward policymakers' goal of eliminating the disease altogether.
"It would bring us many steps closer to overhauling an outdated program that has failed to adequately protect miners from breathing unhealthy levels of coal mine dust and achieving the intent of Congress to eliminate black lung disease,” Joseph A. Main, head of the Mine Safety and Health Administration, said in a statement.
Still, NIOSH has warned that cutting the PEL in half won't eliminate black lung altogether.
"Even at the 1 mg/m3 coal mine dust exposure limit," NIOSH said in August, "some occupational effect on ventilatory function is expected."
The public will have 60 days to comment on the proposal after it's published Oct. 19 in the Federal Register.