Mining Contract: Respirable Crystalline Silica Characteristics and Sources in U.S. Underground Coal Mines

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Contract # 200-2019-05528
Start Date 9/1/2019
End Date 8/31/2021
Research Concept

A study to characterize the relative toxicity and contribution of respirable crystalline silica from specific dust sources using coal dust samples from working mines and samples representative of major dust sources within mine in order to better understand each element's potentially unique contribution to the development of silicosis, as well as other lung diseases, such as coal workers' pneumoconiosis (CWP) and its most severe form, progressive massive fibrosis (PMF).

Contract Status & Impact

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Respirable crystalline silica (RCS), which generally occurs as quartz in coal mines, has long been recognized as an occupational health hazard. For decades, the mass content of quartz in respirable dust has been measured in U.S. mines as a means of monitoring RCS exposures. However, a recent surge of severe and rapidly progressive disease linked to RCS suggests that conventional monitoring might not yield sufficient understanding of health risks. In turn, conventional dust control strategies might not be effectively focused. A better understanding of the relative toxicity and contribution of RCS from specific dust sources is urgently needed.

This research seeks to address this need by investigating toxicity-relevant RCS characteristics (particle size and surface characteristics) in real coal mine dust samples and in samples representative of major dust sources (i.e., mined coal and rock strata, and rock dusting products). This project is directly related to Recommendation 9 in the 2018 National Academies Study Report on “Monitoring and Sampling Approaches to Assess Underground Coal Mine Dust Exposures.”

Researchers will characterize the particle size distribution and presence or absence of particle surface occlusion in RCS from real coal mine dust samples and will evaluate major source contributions by comparison of these characteristics between mine dust and source-dust samples. The primary outcome of this work is expected to be a more complete understanding of where and how toxicity-relevant RCS characteristics occur and vary within and between various mine environments.

Page last reviewed: March 25, 2022
Page last updated: March 25, 2022