Condition Basics

What is black lung disease?

Black lung disease is a common name for any lung disease that develops 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 (CWP). There are two forms: simple CWP and complicated CWP, which also involves progressive massive fibrosis (PMF).

The inhalation and accumulation of coal dust into the lungs increases the risk of developing chronic bronchitis and chronic obstructive pulmonary disease (COPD). Although black lung disease may share many of the symptoms of COPD, it is not COPD and is not treated like COPD.

What causes it?

The inhalation and accumulation of coal dust causes black lung disease. This stems from working in a coal mine, doing 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 black lung disease 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 black lung disease depends on the type of coal dust, how much dust was in the air, and how long you have been exposed to it.

What are the symptoms?

Black lung disease 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 black lung disease progresses and is complicated by progressive massive fibrosis (PMF), a cough and shortness of breath develop, along with sputum and moderate to severe airway obstruction. Quality of life decreases. Complications of black lung disease include cor pulmonale.

Smoking does not increase the prevalence of black lung disease, nor does it affect the development of it. 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 non-smoking coal workers.

How is it diagnosed?

Black lung disease is diagnosed through an occupational history and chest X-rays. Lung function tests may be used to determine how badly the lungs are damaged.

Occupational history is very important to the diagnosis of black lung disease—if a person has not been exposed to coal dust, he or she cannot have it. The occupational history should include not only recent and past full-time employment, but also summer jobs, student jobs, military history, and short-term jobs.

The diagnosis of black lung disease has legal public health implications, since provinces require that all cases be reported to collect information and in some cases provide compensation.

How is black lung disease treated?

There is no proven effective treatment for black lung disease, although complications can be treated.

In Canada, black lung disease is a reportable disease under the Occupational Health And Safety Act. A case of black lung disease must be reported to the Workers' Compensation Board in each province.

How can you prevent it?

Black lung disease can be prevented by controlling coal dust and having good ventilation in the workplace.