Coal Miners Facing Increased Incidence of Black Lung Disease

Researchers warn about a surge in diagnosed cases of black lung disease among coal miners in recent years, despite increased safety protections. 

A new analysis of U.S. Department of Labor data on coal miners, collected since 1970, identified 4,679 cases of progressive massive fibrosis (PMF), more commonly known as black lung disease. More than half of the cases were diagnosed after 2000.

In recent years, clusters of black lung disease outbreaks have been reported and investigated in isolated coal mining regions. The data indicates a significant increase in black lung disease cases has occurred in the past 20 years, compared to the previous 30 years.

In 2016, 60 black lung disease cases were identified by the U.S. Centers for Disease Control and Prevention (CDC) at a single radiology clinic in eastern Kentucky. The CDC  warned the cases pointed to a drastic increase in black lung disease.

Earlier this year, the National Institute for Occupational Safety and Health reported 550 cases of black lung disease. The cluster originated from three clinics in southwestern Virginia since 2013. It is the largest outbreak of black lung disease ever reported in the U.S.

However, the new analysis indicates the outbreaks are not isolated. They indicate a pattern of increasing cases of progressive massive fibrosis among coal miners. The study is the first systematic attempt to assess outbreaks of black lung disease in former miners.

The increases are occurring despite new rules issued in 2014, by the Mine Safety Health Administration, which lowered acceptable breathable dust levels at coal mines from 2.0 to 1.5 per cubic meter of air in an effort to protect miners.

Researchers speculate that this may be due to changes in mining practices and exposure to high levels of rock dust that contains crystalline silica. Crystalline silica dust is much more toxic to the lung than coal dust.

In 2016, OSHA raised concerns regarding workers exposed to silica dust and increasing incidence of lung related diseases and conditions.

As a result of the recent findings, researchers are conducting an ongoing study to compare biopsied lungs from recent outbreaks to samples from autopsies of miners who died 40 to 50 years ago. They are examining the mineral composition of lung dust to determine if it now consists primarily of silica dust.

Regardless of the results of that ongoing study, researchers warn the increase in black lung disease cases is alarming, as the disease is entirely preventable.

Exposure to dust from mines causes the disease, and there is no other way to contract the ailment. To that end, researchers warn every case of black lung disease is a failure of the system to protect coal miners. Early detection and medical screening should be emphasized to prevent overexposure and disease development.

The findings of the study were presented May 22 at ATS 2018, the annual international conference of the American Thoracic Society. The findings are considered preliminary until they are published in a peer reviewed journal.