Document b51MvXzo6J79y0O0YrOG01zgD

ft jc-*. .-v" T : , ............. ..................................... 4. epidemiological technique sjo their content and.most.of the authors do not ............. make claim to having done eo. Whet ku happened Id that eucceedlng author* have draws conclusions and generalised beyond the scope of the works which they quote. Nowhere, for example, have we found references to a population of asbestos workers, although several authors who have quoted the obsarved Incidence of lung cancer in autopsies of persons who alno had aabcetools imply that this Incidence applies to asbestos workors, generally. We have likewise been unable to find any study which actually calculated the Incidence of lung cancer among a population of persons who had asbostosls, and not just those who came to autopsy. With the exception of a paper by"Doll none of those reviewed gave any data on exposure and dust concentrations, and even Doll's paper merely mentions "scheduled" areas, by which Is meant, "those areas where procossos are carried on which wore scheduled under, the Ashes- toe Industry Regulations of 1931 as bolag dusty." Thera la, furthermore, a complete lack of definition of terms as uesd la the published literature. For example, the term "asbostosls", as used, may refer to changes observable only by microscopic examination.of the lung tissue, or It may mesa a rsdlologlcally dstoctablo condition, Hoil of the publlsbad rsports obviously Included women among their cases, but soms of them do not glvo the number or proportloo of women In volved In the'study. There Is also a lack of uniformity as to what type of exposure most studies have dealt with. Of 99 caess enumerated by Hucpor^^ In J955, only 0253