Anthracose

Black lung disease (BLD), also known as coal-mine dust lung disease, or simply black lung, is an occupational type of pneumoconiosis caused by long-term inhalation and deposition of coal dust in the lungs and the consequent lung tissue's reaction to its presence. It is common in coal miners and others who work with coal. It is similar to both silicosis from inhaling silica dust and asbestosis from inhaling asbestos dust. Inhaled coal dust progressively builds up in the lungs and leads to inflammation, fibrosis, and in worse cases, necrosis. Black lung disease develops after the initial, milder form of the disease known as anthracosis (from the Greek άνθρακας, or anthracas – coal, carbon). This is often asymptomatic and is found to at least some extent in all urban dwellers due to air pollution. Prolonged exposure to large amounts of coal dust can result in more serious forms of the disease, simple coal workers' pneumoconiosis and complicated coal workers' pneumoconiosis (or progressive massive fibrosis, PMF). More commonly, workers exposed to coal dust develop industrial bronchitis, clinically defined as chronic bronchitis (i.e. a productive cough for three months per year for at least two years) associated with workplace dust exposure. The incidence of industrial bronchitis varies with age, job, exposure, and smoking. In non-smokers (who are less prone to develop bronchitis than smokers), studies of coal miners have shown a 16% to 17% incidence of industrial bronchitis. In 2013, BLD resulted in 25,000 deaths globally—down from 29,000 deaths in 1990. In the US, a 2018 study by the National Institute of Occupational Safety and Health shows a resurgence among veteran coalminers, recording the highest rate of BLD in roughly two decades. Coal dust is not as fibrogenic as silica dust. Coal dust that enters the lungs can neither be destroyed nor removed by the body. The particles are engulfed by resident alveolar macrophages or interstitial macrophages and remain in the lungs, residing in the connective tissue or pulmonary lymph nodes.