Diesel Particulate Matter Exposure of Underground Metal and Nonmetal Miners

This proposed rule would establish new health standards for underground metal and nonmetal mines that use equipment powered by diesel engines. The proposed rule is designed to reduce the risks to underground metal and nonmetal miners of serious health hazards that are associated with exposure to high concentrations of diesel particulate matter (dpm). DPM is a very small particle in diesel exhaust. Underground miners are exposed to far higher concentrations of this fine particulate than any other group of workers. The best available evidence indicates that such high exposures put these miners at excess risk of a variety of adverse health effects, including lung cancer. The proposed rule for underground metal and nonmetal mines would establish a concentration limit for dpm, and require mine operators to use engineering and work practice controls to reduce dpm to that limit. Underground metal and nonmetal mine operators would also be required to implement certain ``best practice'' work controls similar to those already required of underground coal mine operators under MSHA's 1996 diesel equipment rule. These operators would also be required to train miners about the hazards of dpm exposure. MSHA has already proposed a rule to control dpm exposures in underground coal mines in a separate notice to the public published in the Federal Register on April 9, 1998 (62 FR 17492).