The study has found that crystalline silica, a component of coal mine dust, was found in the lungs of coal miners which causes severe and irreversible lung scarring.

The study was published in the journal, Journal of Occupational and Environmental Medicine. Researchers examined lung tissue from deceased coal miners and compared findings across specific mining job duties to see which miners were at risk for severe black lung disease.

They found that more recent coal miners with PMF (born after 1930 and working primarily with modern mining technologies) had worked significantly fewer years than historic miners (born before 1930) with PMF.

They also found that scarring from silica dust exposure was more common in contemporary miners, even those whose job duties were not prioritised for dust sampling in current federal regulations such as electricians and foremen.

"Our findings show the importance of monitoring silica exposure in coal miners whose job duties weren't previously considered high risk," said National Jewish Health researcher Lauren Zell-Baran, MPH, who was the lead author of the study.

"Severe black lung disease is incurable, disabling and entirely preventable," said Cecile Rose, MD, MPH, an occupational pulmonologist at National Jewish Health and co-senior author of the study.

"This study underscores the need to control silica dust exposure for all coal miners," he concluded.