THE term pneumoconiosis applies to diseases of the lungs caused by inhalation of foreign material. A more specific diagnosis will depend upon correct identification of noxious substances in air samples, sputum and, whenever possible, lung tissues. Among the occupational hazards causing pneumoconiosis, asbestos has been identified in exposed mine workers, workers handling insulating materials composed largely of asbestos, workers in the brake-lining industry and workers engaged in asbestos spinning, carding and weaving.1 Although asbestos bodies have been found in the lungs or sputum of patients with no evidence of pulmonary disease or heavy exposure,2 the presence of asbestos bodies in . . .