Progress in etiopathogenesis of respiratory disorders due to occupational exposures to mineral and organic dusts.
NIOSH 1990 Sep; :22-24
Recent progress in the etiopathogenesis of respiratory disorders resulting from occupational exposure to mineral and organic dusts was discussed. The emphasis was on mineral dust related lung diseases. It was asserted that there is no such disease as byssinosis. The biological effects of cotton dust should be included under the category industrial asthma. It was suggested that silicosis is a disease of the monocyte macrophage system in which inhaled quartz (14808607) crystals destroy macrophages, which produces a local medium that promotes infection by mycobacteria. Tumors induced in some studies in experimental animals by exposure to quartz were attributed to a nonspecific effect not associated with silica. Coal workers' pneumoconiosis (CWP) was discussed. The disability associated with complicated CWP is due to associated emphysema and interstitial fibrosis and not the result of nodulation. The main constituents of the nodules has been shown to be fibronectin and not fibrous tissue as previously thought. Asbestos (1332214) associated diseases were reviewed. The mineralogical characteristics of asbestos fibers, asbestos bodies, pleural plaques, lung carcinoma, and diffuse pleural and peritoneal mesotheliomas were discussed. Mesotheliomas are primarily associated with exposures to crocidolite (12001284) and very fine chrysotile (12001295) and tremolite (14567738). Studies with man made mineral fibers (MMMFs) and absorbent clays were described. Erionite (12510428) has induced a high incidence of mesotheliomas in laboratory animals after intrapleural injection or inhalation exposure. The mesothelioma incidence was much higher than in animals exposed to asbestos. The author concludes that erionite is a very potent carcinogen. It may be of value in elucidating the pathogenesis of mineral fiber mesothelioma.
Respiratory-system-disorders; In-vivo-studies; Laboratory-animals; Lung-cancer; Cigarette-smoking; Mineral-dusts; Asbestos-fibers; Occupational-exposure; Occupational-respiratory-disease;
14808-60-7; 1332-21-4; 12001-28-4; 12001-29-5; 14567-73-8; 12510-42-8;
Asthma and Chronic Obstructive Pulmonary Disease; Disease and Injury; Respiratory-system-disorders;
Proceedings of the VIIth International Pneumoconioses Conference