Document vB7Go2w8kgj93zO894JzrLQ2Z

- 86 - It ie desirable that National Statistical Agencies and Bodies apply the who International Classification of Diseases to distinguish between X* .Primary pulmonary and pleura) malignant neoplasms, and ?. Primary peritonea) malignant neoplasms. Certain selective processes operate through the above sources so that the number of cases will not necessarily be the some, and the use of all sources is likely to ensure the most complete cover, both of these believed to be occupationally linked and those in which the occupation was not thought to be invol ved or in which no adequate investigation of the occupation was made. In addition an examination of the fibre content of the lung should be per formed wherever possible. Reports through pathologists and clinicians will Include both occu pational and rion-occupationa) cases. In view of the high end rapid mortality of those cases, the majority will be detected by pathologists or clini cians snd appear in official statistics, but there may be exceptions. The reports through the pathologists and clinicians have the advantage that they may provide a means for detailed investigation of the occupational histories while the individual is alive, and this could be of considerable help in impro ving the information about associated occupations and 3bs. It is a vcllknown fact that the diagnostic criteria for mesothelioma, as given above have not always been adhered to, particularly in older Etudies, and the conclusions sometimes may have to be enweakened. In 1971 Wagner et a) reviewed the evidence available at that time. Their review is surv.ari *ed as follows: Nearly all cases of mesothelioma (pleura and/or poiitcr.eum) in Britain ap pear to be of occupational origin and not the result cf contamination of the genera) erwirenment. In .shout lO-l&t of cases where information on past history has been cotr.plcte, -to hit-lory exposure has been recorded end few or no asber'os b*;-di.s h.xvc^lw'onVCctectc-d in the lung. In Britain mesotheliomas pax tic::lr)y cccur i/Tr-;.rts .-.nd in cities with factories where asbestos has bern handled in lesge amounts in the past. Exposure to croejdolite apparently carries the greatest risks. Exposure to pure chrysctile or to anthcphyllite provides hardly any riskj in the m03 de> ptv 19' (c. (C. uer c;.. di. fr. t::< to of In: .`.x: C J. Bf>Dl r*7'? PRODUCED BY FORD