Current Intelligence Bulletin 64

Since its inception in 1970 the National Institute for Occupational Safety and Health (NIOSH) has extensively investigated and assessed coal miner morbidity and mortality. This history of research encompasses epidemiology; medical surveillance; laboratory-based toxicology, biochemistry, physiology, and pathology; exposure assessment; disease prevention approaches; and methods development. The experience gained in those activities, together with knowledge from external publications and reports, was brought together in 1995 in a major NIOSH review and report of recommendations, entitled Criteria for a Recommended Standard-Occupational Exposure to Respirable Coal Mine Dust. This document had the following major recommendations: Exposures to respirable coal mine dust should be limited to 1 mg/m3 as a time-weighted average concentration for up to a 10 hour day during a 40 hour work week; Exposures to respirable crystalline silica should be limited to 0.05 mg/m3 as a time-weighted average concentration for up to a 10 hour day during a 40 hour work week; The periodic medical examination for coal miners should include spirometry; Periodic medical examinations should include a standardized respiratory symptom questionnaire; Surface coal miners should be added to and included in the periodic medical monitoring. This Current Intelligence Bulletin (CIB) updates the information on coal mine dust exposures and associated health effects from 1995 to the present. A principal intent is to determine whether the 1995 recommendations remain valid in the light of the new findings, and whether they need to be updated or supplemented. The report does not deal with issues of sampling and analytical feasibility nor technical feasibility in achieving compliance.