Black lung disease
Black lung disease is the common name for coal workers' pneumoconiosis (CWP) or anthracosis, a lung disease of older workers in the coal industry, caused by inhalation, over many years, of small amounts of coal dust. Black lung disease has gone by many names, including anthracosis, black lung, black spittle, coal worker's pneumoconiosis, miner's asthma, and
silicosis. (Pneumonoultramicroscopicsilicovolcanosconiosis has been alleged to be synonymous with black lung disease but it is not.)
Since the particles of fine coal dust, which a miner breathes when he is in the mines, cannot be destroyed within the lungs or removed from them, builds up. Eventually, this build-up causes thickening and scarring, making the lungs less efficient in supplying oxygen to the blood. Black lung results from inhaling coal dust over a long time. Although coal dust is relatively inert and does not provoke much reaction, it spreads throughout the lungs and shows up as tiny spots on an x-ray. Coal dust may block the airways. In simple black lung, coal dust collects around the small airways (bronchioles) of the lungs. Every year, 1 to 2% of people with simple black lung develop a more serious form of the disease called progressive massive fibrosis, in which large scars (at least ½ inch in diameter) develop in the lungs as a reaction to the dust. Progressive massive fibrosis may worsen even after exposure to coal dust stops. Lung tissue and the blood vessels in the lungs can be destroyed by the scarring.
The primary symptom of the disease is shortness of breath, which gradually gets worse as the disease progresses. In severe cases, the patient may develop cor pulmonale, an enlargement and strain of the right side of the heart caused by chronic lung disease. This may eventually cause right-sided heart failure. Some patients develop emphysema (a disease in which the tiny air sacs in the lungs become damaged, leading to shortness of breath, and respiratory and heart failure) as a complication of black lung disease. Others develop a severe type of black lung disease called progressive massive fibrosis, in which damage continues in the upper parts of the lungs even after exposure to the dust has ended. Scientists aren't sure what causes this serious complication. Some think that it may be due to the breathing of a mixture of coal and silica dust that is found in certain mines. Silica is far more likely to lead to scarring than coal dust alone.
Black lung disease can be diagnosed by checking a patient's history for exposure to coal dust, followed by a chest x-ray to discover if the characteristic spots in the lungs caused by coal dust are present. A pulmonary function test may aid in diagnosis. X rays can detect black lung disease before it causes any symptoms. If exposure to the dust is stopped at that point, progression of the disease may be prevented.
There is no treatment or cure for this condition, although it is possible to treat complications such as lung infections and cor pulmonale. Further exposure to coal dust must be stopped. Black lung can be prevented by adequately suppressing coal dust at a work site; ventilation systems may help. Face pieces (masks) that filter and purify the air may provide some additional preventive benefit.