Document jB0byXra9NXDV9G73G7k0Oorp

LVNG CANCER IN ASBESTOS MINERS Taju IS.^'wafrfr Omd PtTftntBft Distribution of Smoktfi a**d Nontmoktrj fry ___.... /^iw# Ccitgon Scmot Cimwy aotin UO Mi 1.0 KmaMm fl< U 0 U TuJ___ .... woji Ulksevg Si 1 iu Due i eerned, the smokers had worked about 2J years ku on the average than the ndnunokers. With longer exposure and greater age, one would expea the nonsmoking group to show a higher rate if lung canter were due to asbestos. Table la shows that the average exposure category was almost the same for the two groups. Therefore, this variable scons to be of oo importance in accounting for this difference. The result of this additional analysis is that none of these factors appears to lessen the effect of Tabic 12. Comporijon of the Cohort Experience with that of the Province of Quebec, Do minion of Canada, and the United Stotet.-- In order to make a comparison of the experience among asbestos miners with that of the general population of the Province of Quebec, statistics were gathered, as stated earlier, in the office of the Division of Demography in the Provincial Ministry of Health. The dau on total deaths, deaths from all forms of cancer, and deaths front Cancer of the lung were obtained by sex and-by county for the years 1930 through 1933. In addition, all death certificates which specified primary cancer of the lung, and all those which indicated lung cancer but did not specify the origin, were exam ined for the years 1952 through 1955. Table 16 gives a tabulation of the number of deaths from lung cancer in the Province and in the cohort for the years 1950 through 1953, and shows the annual rate per 100,000 in these segments. It win be noted from the table that the mortality rate for the "proved" cases in the cohort is only slightly higher than the rate for the Province. When the "suspected" cases are included in the calculation, the rate for the cohort rises to 35.8 per 100.000, which is about 50** higher than the rate for the Province. This, it will be recalled from the previous dis cussion of the effect of the "suspected" cases on the results, approaches but does not exceed the significant level One further interesting observation from Table 16 is the rather marked increase in the total number of cases for the Province between 1930 and 1953. It is assumed that at least part of this increase b due to im proved recognition and teporting of lung cancer during the interval. For thb reason, the years 1954 and 1955 were thought to be more nearly representative of actual condi tions Even so. it is quite likely that the general population is not studied for lung cancer with the same diligence with which Tana 16.--Companion of Cohort with Prontte of Qmbee Nntoraf . lui Cue* Dntli fpvu tsa ml im tsa mt ms ,i 9 ttM0COB* m liS f as M SO ' w s i s ) t i > < us M m as SM > RMtOtT T NBAS U* VS IS US f uu Si ta tt fwnow Blwi Iw Mo waM 8 cato tent otar 6<nla w la. wt, A#o"Mta ertpavaafinrcftasvmadfspQ&uoaJof pipauw far IIM ffappwv (Hr. 4a to Of* tSom&aeabvttDfvMrtft bamftlftf H \UL Trman fr4j