Document Yrd27v1eE5NOaxqeLLaKz6L20

| \ i i ' i i \ i i ' f > i ( 1 - ion ns Manx i \.\.v. ('owrnh\\Tio\ rw i n ) V i*n 11 i. \* > i i; i r. i 11 " i m ' > r \ l Av > ` >u K : ^ ' Dece.:.oer jC, 15?? hr. I var, Sac-cur in St. Joi.ne Quebec ,,*or ivan: t Re: I.H.F. Survey >iugn Jackson arid I nave reviewed tr.e ccacer.sstion of the survey which yo- sent us. We nave noted deletion of all references to the association cf asoestosis and lung cancer in tnis condensation. While we believe tnat this infermatien is of great scientific value, we can understand the desire of the Q.A.K.A. to emphasize tne exposuro of the accestos miner and not tne cases of asbestosis. We also are in agreement with the deletion of the reference to smoking and lung cancer. It must be recognized, however, that*tnis report will be subjected to criticism when publisnea because all other authors today correlate lung cancer a.-iw cases of asoestosis. If we are to restrict this condensation to asbestos miners, greater-emphasis should be placed on tno choice of words used in defin ing tn conort.- The fact tnat all members of tne cohort had 5 or isore years of exposure to asoestus should be reiterated. Following are comments on certain paragrapnc of the condensation. We believe the first sentence in paragraph 2 should read "Perhaps no one nar written so extensively iw;e id In the third sentence cf paragraph 2 tne definition of cohort should be expanded to emp;iasise tnat nen-expesed pt-mense! were net included in the sample. T1..5 nugni l*s done by auding a sentence similar to tne following: "office and otner non-cx.pcsed personnel, regardless of lengtr. of employment were not included in tne- cu/iorf*. Face lb To further emphasize tne exposure aspect of the miners tne second sentence of paragraph 2 might read, "All workers with more tnan 5 years of ex posure were placed in one of three categories". it mient be auvleable to add another sentence at the end cf tnis para graph, "Ai< previously noted workers with no exposure were not ir.ci.uaed in the cats" .lx. Ivan Sakcurin 2 3C} 1.3" . <a 7,, s In one fourth sentence reference is mace to "tne ?$% level of cance". This onrase vas explained clearly and 'u:.c: ougnly on Pogue 23 v rr id socii.cn on Statistical Methods of tho original surv 5y. i^eenuse thun w;; ue sec icn was deleted in the condensation we feel it migr.t be anvisacle to ex^la! cy fc note the meaning of "the ?5* level cf significance". Wo feel tnat the fifth sentence right be made stronger by tne following change, "However, having found oust 13 cases, we arc not above this level, ar.a therefore the hypotnesis that asbestos miners do not nave a higher .mortality from lung cancer than does the general population cannot be rejected". Eage hi The table in the center of the page ehova a rate of 271 in tne 15 - 51 age group. In the original survey this rate was 27. Pace lo In the last sentence of tne first paragraph we would like to suggest the substitution of the word "undertauten11 for the vera "commissioned". in the second sentence of paragraph 3 ve'would like to suggest tiiat the elements of tne cohort definition be repeated. "A cohort was defined as a group of asbestos miners naving at least 5 years of e^osure in the indstry and who were in the industry during 1950. Only those workers who met these criteria were in cluded in the etudy". Page 19 1 In the last sentence of paragraph 1 va would like to suggest the dele tion of the phrase "vnich have been explained in some detail" since such explanation was deleted in the condensation. Tms publication should form the basin for-future"' surveys and reports. jr. hraun snoula be asked to establish tne framework of reporting for Doctors Grainger and Cartier 30 that each year the status of every member of the original cohort coula be reported to the Industrial Hygiene Foundation and the continuing study be analyzed by their experts. We cannot emphasize this point too strongly because novnere in the litoratuxe today is there reported a study which is so valuable and which approximates this magnitude. We agree with Doctors Cartier and Braun bnat a certain number of workers probahly have some asbestotic fibrosis wr.icn cannot bo diagnosed by x-ray. Un fortunately, wo cannot take lung biopsies cn all workers and we have no other means oi making a diagnosis before there are x-ray changes. Therefore the annual study of all exposed asocstcs workers becomes increasingly important.. We feci that Dr. braun ana :iis staff are to be congratulated heartily for this very valuable contribution to our medical knowledge. We trust that their eJ'Jwrts will be rewarded m the near future by the publication of tins work in a recognized journal. Sincerely, Kenneth W. Smith, M.D. Medical Director