The review, released last week by the National Academies of Sciences, Engineering, and Medicine, "notes that coal mine operators comply with the new dust control regulations at a rate of more than 99 percent, but 'these approaches may not guarantee that exposures will be controlled adequately or that future disease rates will decline'," Howard Berkes reports for NPR.
Mine operators need to do more than comply with federally mandated safety requirements to lower the incidence of black-lung cases, the review concludes, and says a "fundamental shift is needed in the way mine operators approach exposure control."
The latest rules, imposed in 2016, require a small number of miners to wear dust-sampling devices that monitor coal-dust exposure in real time but can take weeks to analyze. If the monitors discover unsafe dust levels, mine operators can boost ventilation, slow mining machines so they produce less dust, and move miners to areas with less dust, but the study found those approaches inadequate, since miners in other areas who are not wearing the devices may be exposed to more dust.
"Also, the new dust monitors do not provide real-time sampling of silica dust, which is created when mining machines cut into sandstone and is far more toxic than coal dust alone," Berkes reports. "Cutting sandstone has occurred more often in Central Appalachia as large coal seams are mined out and the thinner seams that remain have sandstone mixed with the coal." The study recommends development of a real-time silica dust sampling monitor. The National Institute for Occupational Safety and Health is working on such a device, but already has a system that can provide silica exposure readings at the end of a miner's shift; that device is expected to be available to mining companies for voluntary use soon, Berkes reports.