Document emeweaMGX6onnxeEaqjyGL9XG

ASBESTOS IS 1, First described in 1899 in London 2, 1930's - Asbestosis shown to be a major cause of DISABILITY IN WORKERS IN ASBESTOS TEXTILE INDUSTRY 3, Latent period of 10 - 20 years A, Symptoms & Signs A, Early a) Shortness of breath b) Chest pain ' B, Later c) Basal rales d) Clubbing of fingers e) X-ray changes f) Abnormal lung function DUP 1005305 DU 050942 PLEURAL THICKENING 1, Occurs early 2, May be only change 3, Not a feature of other kinds of pneumoconiosis 4, May become calcified a, Rarely occurs, i-Nless. than 20 years after first exposure b. Feature of anthophyllite exposure Ci Exposures not always occupational DU 050943 DUP 1005306 ASBESTOS BODIES (FERRUGINOUS ROniFS) 1, Fibers coated with an iron-containing protein which GIVES A CHARACTERISTIC GOLDEN BROWN BEADING ALONG THE LENGTH OF THE FIBER 2, Thickened at each end to form a characteristic DUMBBELL APPEARANCE 3, Asbestos bodies in lung or sputum not pathognomonic of asbestosis 4, Lungs from urban areas contain typical asbestos BODIES IN SMALL NUMBERS 5, Other mineral fibers can become coated in the SAME WAY DU 050944 DUP 1005307 THEORIES OF PATHOGENESIS OF ASBESTOSTS 1, Original theory of physical irritation 2, Solubility theory 3, Autoimmune theory 4, Stagnation of phagocytes' theory DU 050945 BRONCHIOGENIC CANCER 1930's - Association between asbestosis and BRONCHIAL CANCER WAS DISCOVERED, ESPECIALLY IN ASBESTOS TEXTILE WORKERS Association appears to be with asbestosis rather THAN SIMPLY EXPOSURE TO ASBESTOS DUST Cigarette smoking is an important additional and POSSIBLY SYNERGISTIC FACTOR Latent period of 20 - 30 years DU 050946 DUP 1005309 ESQIHEUM Diffuse cancer spreading over surface of lungs (pleura) AND ABDOMINAL ORGANS (PERITONEUM) Associated particularly with crocidolite exposure Asbestosis is often absent Latent period of AO years Smoking has not been ^shown to _be a contributory factor Exposures not always occupational DU 050947 DUP 1005310 CARCINOGENIC BEHAVIOR OF ASBESTOS (Possible Mechanisms) F ,1. Metal complexes found in asbestos naturally - e Cr, Ni 2, Oils associated with asbestos a, Naturally occurring b, Jute oil from sacks c, Emulsions added'for processing 3. As A COCARCINOGEN 4, Prolonged residence in tissue of chemically-inert MATERIAL - OPPENHEIMER EFFECT DU 050948 DUP 1005311