Mining Project: Particulate Measurement and Characterization in Mining

Research Summary

Measurement and monitoring of coal mine dust, silica dust, and diesel particulate matter in underground coal and noncoal mines continues to be problematic. Surveillance data on black lung disease among coal miners has shown an increase over the last 10 years from about 6%-11% of workers with 25 years of mine experience. NIOSH has proposed that silicosis may be a significant contributor to this lung disease trend. The United Mine Workers of America, Bituminous Coal Operators Association, and National Mining Association need this research to help reverse this new trend. This area may be particularly relevant given the proposed reductions to the permissible exposure limits for both coal mine dust and silica dust.

Because of the potential health hazards associated with airborne respirable dust and diesel engine emissions, the Mine Safety and Health Administration (MSHA), labor, and the mining industry are proponents of accurate real-time or near-real-time measurements. Feedback on worker exposures in real time will allow for adjustments during the shift in order to prevent overexposures. The research in this project focused on the development of instruments to better monitor respirable coal, silica dust, and diesel particulate matter (DPM).

This project developed innovative instruments and methodologies for real-time measurement of respirable mineral aerosols and diesel particulate matter aerosols. This proposed research supports the NIOSH strategic goal to reduce work-related illnesses through the generation of new technical and scientific knowledge on aerosol measurement. Measurement of silica from filters used in personal dust monitors was evaluated and licensed. Research to explore the feasibility for an end-of-shift monitor that is specific for the silica component of a respirable dust sample was also initiated and was continued under the project, "Monitoring and Control of Airborne Toxic Substances in Mining." Use of personal dust monitors (PDM) by MSHA under 30 CFR 74 was an outcome for this project. A near-real-time personal monitor for DPM was also developed by NIOSH and was commercialized. This method may also be useful for determining tailpipe particulate for maintenance issues.