Pneumoconioses
Pneumoconiosis describes the pathological reaction of the lung to inhaled dust, which is most frequently, but not necessarily, one of fibrosis, and most often, but not exclusively, related to exposures occurring at work. It may be more formally defined as a permanent alteration of lung structure due to the inhalation of mineral dust and the tissue reactions of the lung to its presence, excluding bronchitis and emphysema. Lung damage occurs when respirable dusts reach the acinus in sufficient quantity to overwhelm the normal phagoctyic and clearance mechanisms. The causes of pneumconiosis are many and varied, but many epidemiological studies have shown an exposure–response relationship between the total mass of respirable dust to which workers have been exposed and their risks of developing disease. These form the basis of regulations specifying limits to permitted levels of exposure. Workers, whose exposure results in pneumoconiosis, may be entitled to compensation in some countries....