What is black lung disease?

Black lung disease is a type of pneumoconiosis, a condition caused by breathing certain forms of dust into the lungs. Specifically, black lung disease is caused by inhaling coal dust, which tends to blacken the lungs instead of their normal pink color. It occurs only among workers in coal mines, or those in other work situations that cause high exposure to coal dust. It may alternatively be called coal workers' pneumoconiosis (CWP). When the disease has progressed significantly, it develops into progressive massive fibrosis (PMF) and is responsible for the deaths of thousands of coal workers annually, even if exposure to coal dust ended years earlier.

Black lung disease is not chronic obstructive pulmonary disease (COPD) and it is not emphysema. However, having the disease, which can simply appear as a cough in the early years, makes you more vulnerable to developing any of these conditions. If the condition is caught early, it may be possible to stop the progression of the disease, either by employing increased safety practices around coal dust or by ceasing work around coal dust. Smoking can worsen other diseases that will make black lung disease more challenging, significantly increasing the risk of COPD, emphysema, and lung cancer.

The condition can only be caused if people work around coal dust, and the specific mechanism of the disease makes this understandable. When charcoal is inhaled, it can combine with white blood cells called macrophages. This combination of dust and blood cells begins to create abnormal tissue in the lungs called nodules. As the nodules increase in size, they begin to restrict airflow, causing lower blood oxygen levels and then extreme difficulty breathing.

Continued exposure to coal dust means more nodules will form, greatly increasing the risk that at some point a person will not be able to breathe without assistance and creates a risk of disability and death. In general, if the nodules are at least 1 centimeter (about .4 inches) in size, black lung disease is considered to have progressed to PMF. There are no cures for PMF, but if the disease does not progress to PMF, it can have minimal effects on daily life.

However, not everyone with the disease will progress to PMF, especially if they are no longer exposed to coal dust. It usually takes about 10 years of inhaling coal dust for black lung disease to develop, and since it can be asymptomatic at first, people may not notice it. Chronic cough developed by a coal worker is a reason to see a doctor. However, as history has proven to be a major handicap for many who work with coal, economic concerns can keep people working despite the health risk, accelerating the development of PMFs.

Diagnosis of black lung disease is made through medical history and x-rays of the lungs, which may show spots where nodules have formed. Information on respiratory disorders, breathing difficulties and chronic cough is also valuable in diagnosis. If in its early stages, affected individuals can still live fairly normal lives, especially if they change their work environment. Some people benefit from supportive treatment such as access to oxygen or through the use of inhalers such as asthma inhalers.

Unfortunately, there is no cure for PMF, and it has claimed the lives of thousands of coal workers. Safer mining practices, especially in developed countries, now significantly reduce the risk of exposure to coal dust. Black lung disease still affects many of those who worked before such safety standards were adopted, and also those who work in developing countries, which do not have such standards.

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