Document O3jBz2q0VNdBjNbL5RQ5XyqkL

80 - Animal experiments proved that all sorts of asbestos Induce mesothelioma if introduced into the pleural cavity. Inhaled asbestos fibres may reach this cavity in a mechanical way* the. arr.phibole types - especially crocidolitc with their peculiar shape of* fibre, have to be looked upon as the most danger ous (see chapter JV). V, Being mostly an occupational disease in heavy industry mesothelioma is observed more frequently in males than in females} however observations have boon made of a high incidence of mesothelioma in females who worked in a fac tory of crocidolitc containing gas-masks during World War II. There is a long latency period varying from IS to 40 years. Diagnosis of mesothelioma is difficult, the symptoms easily leading to false diagnoses (see chapter JX). P-oth factors - latency period and difficul ty of diagnosis - ..xplain the late discovery of the /rrocintion with asbestos. 4. Peritoncal mcsothelioma (see chapter 1X-4). This is the same type of tumour, but now starting from the mcsothelial lay ers of the peritoneum. An association with uptake of asbestos has to be accepted. As in pleural mcsothelioma,occupational exposure may load to an excess incidence. The . sbosto:*-fibres in these cares arc probably ingested in appreciable q.Mni.j t j es, either directly or indirectly. !r: other Cites growth of 6 pleural r*cscth*`licr.ta through the diaphragm is so^n. In peritoneal mesothelioma the latency period is also long. is fatal} there is no known cure. The disease 5. Cancers of gastronintestlnal tract (see chapter lx-4) rpidcniologjcal investigations in of as.r rtcc-insul ators - heavily exposed workers - proved on excess r.rrtnl l by by^Ss^cer of the gastrointestinal tract. Comparison with the r.crteliiy r^'e-sV^ . on-.*>:pc-ftd groups leads to the conclusion nrbcctcs v.pt'.kc is n c.*usc of tt.'S r.xccns incidence. BO 01 0773 PRODUCED BY FORD