Document VjK98nO3dkqkzo8dqpyXbRgqo

rf'RIAL HEALTH *l'.VG CASTER IX ASHISTOS MIXERS' of pneumoconio- Ucalli certificate it wax iml mentioned, may 169 eases which Save been missed. The import of this 16% type of pneumo- it enhanced by the simultaneous statement loyne considered pat the incidence of lung cancer in aulopstos workers" \r lies of die general population is only 1%. all, it is obvious '[he danger of attempting to eumjiarc a d with the "mor- ' ste found iu 344 cases with the rate for and secondly, te general imputation without respect to that all of. Dr. ge, occupation, and many other variables, itted to him for ' ach as smoking habits, is obvious: were unusual ' Lynch," who with Smith * had reported coniosis. It can ^e firt case in 1935, reported 4 cases of . cases, including .Ijrcinoma of the lung in a series of 49 lich the findings -jutopsies on workers in an asbestos manu al were not sent icturing plant who were shown to have dion. As a mat `^demonstrable deposits of asbestos in the 'agraph in whirh 'ap." This, of course, is m>t necessarily r the incidence ojentical with the disease asbestosis. Lynch, Gloyne himself Jinself, points out that, although this is an for lung cancer fsidence of 8.2%. "Ituth figures .-ire wo i London Chest trail for very serious statistical lv|ics of | the figures of Lieuladon." Nevertheless, later writers .ved only 2.4%. Cye used this paper to strengthen the case topsies on a ccr- *n- an association of carcinoma nf the lung s were not rep- Ifth asbestosis. It is also of interest that population. Ii \toti ** found only the same number of withstanding the lues of lung cancer in a series nearly 10 its.importaucv unes as large, i. e.. 4 in 478 cases of icc of lung can- Lbestosis. i misinterpreted jBchrens, as cited by Merewether,,< estihim. All that it ^ted that, of 309 cases of asbestosis in the t in a grtiup of t^jature, 44 showed' associated cancer of jcial study pri- lung--giving an incidence of 14.2%. d abnormal by H;s is an illustration of generalizing an , or 14.1%, had thence obtained in a group of cases rhich were undoubtedly reported only ben the report of : mu some of them showed lung cancer, to tories, reviewed assibly hundreds of asbestotics .whose 1924 and 1946 ucs were never rqmrted. The same ap- cause of death - fits to the conclusion of Telefcy,** who This work was Wars to have reviewed rqmrts of 39 I such cases re- jtopsics on [icr.sans with asltextosis among 1, by which time Jhich 6 cases of lung cancer occurred. Inding 205 males jrmation front sources such as these does them were 55 ot justify generalizations with regard to the lung, 41 in srtality rates. is quite possible Perhaps no one has written so cxtciistoticx who did Ktly on the subject as has lluejwr.85*' . or iu whose t 1955 he reviewed the cases** reported priur to ilwi .talc amt enumerated a total of 99. Eleven of these wens those dis cussed by I loll ** and may liavc been cases cnvernl by other authors. Eight were dis covered by Keniiaway and Kennaway * in an aiudysis of death certificates, and, unless Mcrewcihcr's study was incomplete, these cases should have been included in his re port. Of the remaining 80, it is ipiite ptissible that the 31 contributed by Mercwclher and the 17 by Gluviic contain sonic duplica tion with each other or with those of other English authors. Principles of the Epidemiological Method Dorn** has pointed out that much of what is now thought to be |>ertincnt concerning the cominitive frequency of lung cancer in different imputation grnujis has been dcvclti|icd frutu tile analysis of cliuicnt ma terial, particularly surgical and autopsy records, supplemented to some extent by the reported impressions-of various clini cians based upon their personal observa tions.. More recently, however, attention has turned to the systematic investiga tion of this problem by the same methods that have proved so successful previously in the study of communicable diseases, that is to say, by epidemiological methods. In order to apply this method of investi gation to the problem under discussion, we were of the opinion that a study should be planned so as to provide (1) a well-defined population group; (2) available data for all members of 'this population, including the healthy as well as the ill; (3) a sample which is truly representative of the imputa tion; (4) reliable and valid observations relating to the problem of the study. A serious defect, common to most nf the studies which have been reported, is that little or no information concerning the healthy people in the group seems to have bc^n available to the author. In order t draw a generalization regarding all aslieslns workers, it Is necessary for a study to in clude living persons as well as the dead. of. IT, June, ]9}.V ufn--Tntan 637 yawn'