Pneumonoconiosis is the term given to a group of diseases of the lungs which arise from the inhalation of irritating particles in the dusts associated with occupations such as coal-mining (anthracosis), steel-grinding (siderosis), quarrying in slate and gold mines (silicosis), and the manufacture of asbestos articles (asbestosis). The disease leads to a fibroid thickening of areas of the lungs, the severity of the condition varying with the type of dust inhaled and the duration of exposure to the irritating agent. In some cases there may be inflammation, ulceration, and cavity formation in addition to the fibrous thickening, and the subject is liable to develop pulmonary tuberculosis. Gradual loss of health with persistent cough and expectoration of purulent sputum (black in anthracosis) indicate the condition. Treatment is carried out on the lines of that for chronic bronchitis or pulmonary tuberculosis. The adoption of hygienic industrial conditions and preventive measures in factories have lessened the incidence of this disease.