Particle size and mineralogy distributions in respirable dust samples from 25 US underground coal mines

Detailed characterization of respirable coal mine dust is critical to understanding occupational health outcomes, as well improving exposure monitoring and controls in mines. However, data on characteristics such particle size mineralogy are still scarce, there virtually no datasets available that allow direct comparisons across many Following up a previous effort characterize from eight underground mines the Appalachian region United States, current study expands dataset cover total 25 country. A 171 samples were collected standard locations each analyzed by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX). Results demonstrate significant differences distributions exist both within between based sampling location, and/or mining method–and can be indicative sources. In nearby production or roof bolting, was clearly sourced strata. Interestingly, location rock-strata appeared inordinately abundant relative actual rock strata heights being mined during sampling. With respect size, diesel particulates generally found finer than mineral dust; likely associated dusting products. On average, when considering all particles 100 10,000 nm, results indicate about 75% submicron range, however these estimated account for only 6% mass.