Coal worker’s pneumoconiosis
Overview
Black lung disease, also known as coal workers' pneumoconiosis (CWP), is caused by long exposure to coal dust. It is a common affliction of coal miners and others who work with coal, similar to both silicosis from inhaling silica dust, and to the long term effects of tobacco smoking. Inhaled coal dust progressively builds up in the lungs and is unable to be removed by the body, leading to inflammation, fibrosis, and in the worst case necrosis.
Symptoms
Both CWP and mild complicated CWP are often asymptomatic or only affect lung function slightly. Shortness of breath and pain may be felt. However, progression to PMF is marked by lung dysfunction, pulmonary hypertension, and cor pulmonale.
Diagnosis
* History of exposure to coal dust * Chest CT or chest x-ray Diagnosis depends on a history of exposure and chest x-ray or chest CT appearance. In patients with CWP, x-ray or CT reveals diffuse, small, rounded opacities or nodules. The finding of at least one opacity > 10 mm suggests PMF. The specificity of the chest x-ray for PMF is low, because up to 1/3 of the lesions identified as being PMF turn out to be cancers, scars, or other disorders. Chest CT is more sensitive than chest x-ray for detecting coalescing nodules, early PMF, and cavitation. Pulmonary function tests are nondiagnostic but are useful for characterizing lung function in patients in whom obstructive, restrictive, or mixed defects may develop. Because abnormalities of gas exchange occur in some patients with extensive simple CWP and in those with complicated CWP, baseline and periodic measures of diffusing capacity for carbon monoxide (DLco) and ABG at rest and during exercise are recommended.
Treatment
* Sometimes, supplemental O2 and pulmonary rehabilitation * Restriction from further exposure Treatment is rarely necessary in simple CWP, although smoking cessation and TB surveillance are recommended. Patients with pulmonary hypertension, hypoxemia, or both are given supplemental O2 therapy. Pulmonary rehabilitation can help more severely affected workers carry out activities of daily living. Workers with CWP, especially those with PMF, should be restricted from further exposure, especially to high concentrations of dust. TB is treated in accordance with current recommendations (see Anaerobic Bacteria: Prognosis and Treatment).