Lung Disease & Respiratory Health Center

What is black lung disease?

Black lung disease is a common name for any lung disease developing from inhaling coal dust. This name comes from the fact that those with the disease have lungs that look black instead of pink. Medically, it is a type of pneumoconiosis called coal workers' pneumoconiosis. There are two forms: simple, which is known as coal workers' pneumoconiosis (CWP); and complicated, which is known as progressive massive fibrosis (PMF).

The inhalation and accumulation of coal dust into the lungs increases the risk of developing emphysema and chronic bronchitis. Coal dust can also increase the risk of developing chronic obstructive pulmonary disease (COPD).

What causes coal workers' pneumoconiosis?

The inhalation and accumulation of coal dust causes coal workers' pneumoconiosis (CWP). This stems from working in a coal mine, coal trimming (loading and stowing coal for storage), mining or milling graphite, and manufacturing carbon electrodes (used in certain types of large furnaces) and carbon black (a compound used in many items, such as tires and other rubber goods). Because CWP is a reaction to accumulated dust in the lungs, it may appear and get worse during your exposure to the dust or after your exposure has ceased.

The severity of CWP depends on the type of coal mine and the dust conditions in the work environment.

Is CWP the same thing as chronic obstructive pulmonary disease (COPD)?

No. Although CWP may share many of the symptoms of emphysema and/or chronic bronchitis (which are also known as COPD), CWP is not COPD and is not treated like COPD.

What is the course of CWP?

CWP starts with the inhalation and accumulation of coal dust in the lungs. For many, there are no symptoms or noticeable effect on quality of life. There may be a cough and sputum (mucus) from inhalation of coal dust, but this may be more a matter of dust-induced bronchitis. As CWP progresses and becomes PMF, a cough and shortness of breath develop, along with sputum and moderate to severe airway obstruction. Quality of life decreases. Complications of CWP include cor pulmonale.

Smoking does not increase the prevalence of CWP, nor does it affect the development of CWP. But it may add to lung damage and contribute to the development of COPD. Coal workers who smoke are at much greater risk of developing COPD than nonsmoking coal workers.

How does CWP affect my lungs?

When coal dust accumulates in the lungs, a coal macule may form. A coal macule is a combination of coal dust and macrophages. As the disease progresses, macules can develop into a coal nodule, an abnormality of the lung tissue. In time, a type of emphysema and fibrosis may develop.

Lung nodules wider than 1 cm (0.4 in.) have been accepted as evidence of progressive massive fibrosis (PMF), although some organizations say a minimum width of 2 cm (0.8 in.) is necessary. Nodules may grow to a large size and hinder or stop the airflow in the lungs' airways.