NIOSH comments on MSHA's proposed rules for respirable dust at surface coal mines, transfer of underground coal miners with evidence of pneumoconiosis, and miner participation by K. A. Busch, June 27, 1980.
NIOSH comments in this testimony concerning underground coal mine respirable dust were directed toward sampling strategy and dust control, designated work positions, the screening level in the sampling strategy, dust control plan, transfer rights, miner participation, definition of respirable dust, personal sampling, and silica (14808607) standard. In the area of personal sampling, NIOSH supports the findings that personal sampling provides the best estimate of worker exposure to the temporal and spatial variations of hazards of the environment in that the worker's personal exposures may be higher than the area monitor level, which may thus provide a false sense of security. Alternatives to personal sampling would decrease the protection of the miners against unhealthy dust concentrations. Support is offered for the recommendation of a 50 microgram/cubic meter standard for silica which is not just for quartz, but for free crystalline silica including quartz, cristobalite (14464461) and tridymite (15468323).