Mining Contract: Respirable Coal Mine Dust: Mineral Content Sources, Monitoring and Control, and Building Capacity to Protect Miner Health

Keywords: Respirable dust Respirable dust level

Contract #	75D30119C05529
Start Date	9/3/2019
Research Concept	Research is needed to better understand, control, and monitor mineral content in respirable coal mine dust. Several studies suggest that mixed mineral dust exposures may be contributing to the burden of disease. Research under this capacity-building contract focuses on advancing the understanding the mining and geological conditions that influence contribution of mineral content, especially strata-sourced minerals such as silicates and silica, to respirable coal mine dust. Such knowledge might provide critical insight to design and operation of mining systems that protect worker health. The contract will also provide demonstration and training opportunities to advance the use of rapid silica analysis by coal mines and develop new expertise in mine health and safety, particularly as it relates to monitoring and controlling respirable dust exposures.

Contract Status & Impact

This contract is ongoing. For more information on this contract, send a request to mining@cdc.gov.

When the Federal Coal Mine Health and Safety Act (CMHSA; 30 US Code, Chapter 22) was passed in 1969, one of its primary aims was to eliminate coal workers' pneumoconiosis (CWP) among U.S. miners. CMHSA set personal exposure limits on total respirable dust and silica and mandated standard sampling and monitoring programs to encourage compliance. It also created the Coal Workers’ Health Surveillance Program (CWHSP), a NIOSH program that provides voluntary health screenings. Following CMHSA, mine monitoring data indicates that total dust and silica levels have generally been declining. However, the prevalence of CWP among U.S. miners has been on the rise since the late 1990s, and cases of the most severe and progressive forms of disease are prevalent in central Appalachia.

Based on chest radiography data and industry knowledge of levels of rock extraction in mines in areas with high numbers of diagnosed patients, silica has been consistently highlighted as potential factor in the recent disease spikes. In response, there have been growing calls to improve silica monitoring, and the NIOSH Mining Program in Pittsburgh has developed a rapid silica analysis capability. The capability would benefit from further demonstration in relation to both validation data and familiarizing stakeholders to help advance the capability toward adoption.

Notably, it remains unclear whether silica is the only factor in the disease spikes. In fact, several medical studies that included lung tissue pathology have pointed to mixed mineral dust exposures, highlighting the possible role of silicates in addition to silica. Recent research has also found an inordinate abundance of strata-sourced mineral content (i.e., silicates+silica) in the respirable dust from many mines. Unfortunately, little is known about which mining and geologic conditions most influence the contribution of mineral dust or the efficiency of modern dust controls to mitigate it. Such knowledge could provide critical insight to dthe esign and operation of mining systems that protect worker health.