Center for Asbestos Safety

Black Lung Disease

Black lung disease is popularly known as the chronic lung condition developed by coal miners. The disease is technically a form of pneumoconiosis called coal worker’s pneumoconiosis (CWP) and can be caused by not only working with coal dust but breathing graphite or man-made carbon for extended periods of time. Although the rates of CWP have plunged since federal regulations came into effect, the number of CWP diagnoses have doubled since 1995.

Coal dust cannot be removed or broken down by the body once it enters the lungs. Clumps of coal dust lodge onto connective tissue in the lungs or in pulmonary lymph nodes. In patients with CWP, these clumps can cause lesions in the lungs. If CWP progresses through years of continued exposure, the condition becomes what is known as progressive massive fibrosis (PMF). In the later stages of PMF, the lungs appear black.

During the initial phase of CWP, there are no symptoms or effect on the quality of life for most patients. Although a cough and mucus may develop, this does not necessarily indicate CWP, as dust-induced bronchitis is very common among coal workers. But as CWP worsens and becomes PMF, the lungs become scarred and a chronic cough and shortness of breath become evident. The patient will also generate severe mucus and their airway will become obstructed.

Most of the people who are diagnosed with the disease are over fifty and have spent most of their lives working in coal mines or in similarly hazardous occupations working with graphite or carbon. Over the last thirty years, stricter safety regulations had limited the instances of CWP, and many thought that the disease would eventually be eliminated except in rare instances. But new data is puzzling researchers and proving that CWP is not a thing of the past. Currently 42,000 coal workers are employed in the United States. In the last decade alone, 10,000 coal workers have died from CWP.
Reported instances of CWP decreased by 90% from 1969 to 1995, thanks to the Coal Mine Health and Safety Act (CMHSA) of 1969 (which was further amended in 1977) that regulated the working conditions of the coal industry. But since 1995, the number of CWP cases has doubled. What is especially startling is the number of young coal miners who have contracted the disease, miners who have spent their entire careers working in the more regulated coal industry that the CMHSA created.

The resurgence of CWP cases has yet to be explained by researchers, but the National Institute for Occupational Safety and Health (NIOSH) lists five possible explanations on its website:

  1. Inadequacies in the mandated coal-mine-dust regulations.
  2. Failure to comply with or adequately enforce those regulations.
  3. Lack of disease prevention measures to accommodate changes in mining practices (e.g. thin-seam mining with cutting of adjacent silica-containing rock) brought by the depletion of richer coal reserves.
  4. The effect of working longer hours in recent years.
  5. Missed opportunities by miners to be screened for early disease and take action to reduce dust exposure.

In response to the raising numbers of CWP diagnosed miners, the NIOSH has launched several programs aimed at early detection and prevention. First among these is the Enhanced Coal Workers Health Surveillance Program (ECWHS), a joint venture between the NIOSH and the Mine Safety and Health Administration (MSHA). The ECWHS offers no-cost health screenings, which include chest x-rays, to mine workers every five years. They also operate a mobile health screening unit that travels to CWP hot spots throughout the country. The NIOSH also runs the Coal Workers X-Ray Surveillance Program (CWXSP) and the National Coal Workers’ Autopsy Program, which is aimed at giving families the evidence the need to make a “black lung” benefit claim and furthering CWP research.

Related: particulate air pollution

Center for Asbestos
Safety in the Workplace