Document jyBKdzmbqELgQXQBJO7kXOxOk

< I - t- PLAINTIFF'S EXHIBIT OnOOb.QD February 28, 1944* Mr. Xvan Sabourln lldred BuiIdlac Montreal, P.y., Canada > Dear Mr. Sabourln: 1 ; I bare your letter of February 22 asking for consents on the relationship between asbestosls and susceptibility to tuberculosis. This question cannot be answered decisively from a study of post aortea material alone. Medical problems of this nature are usually solved on tbe basis of probabilities and It Is this natter of probabilities on which we need further evidence In the case of tuberculosis associated with asbestosls. Merewethsr in his *Meaorandua on Asbestosls* Tubercle i ' -r and Decewber, 1933 and January, 1934) admits that *the data on j are neager.* Be reports that of 374 workers while at work, I _ showed signs of active tuberculosis and that the British Silicosis < . asbestos Medical Board In Its first periodic exartnation of workers In this Industry found only one case of asbestosls and tuberculosis In 1512 ezaalnatlons. On tbs other hand the fiigllsh post nortea material i at that tine revealed 35.7JC of the cases complicated by tuberculosis. (Subsequently be appears to have found aore esses If Dr. Riddell Is cor rectly informed). In the publication cited Msrewsther concludes: The evidence therefore, points to tha hypothesis that Ct present the added risk to asbestos workers froa nulsonarr tuberculosis is Halted and definitely Iwss than in workers exposed to free allies; virulent aasslve Infections will as In the general population, cause death; lesser ones will result in aore widespread fibrosis than would appear In cases amongst the general population and alight Infections, la co.-ann with aaxxy other affections, are likely to precipitate death In cases of advanced asbestosls where they wouldn't do so In the general population.* file underscoring Is mins but I agree with'these Tiers. When Dr. Merewether was In this country last year he visited me for several days and we spent aowt of our tins discussing those problem. Be still accwpts our expwrlnental work which proves that there Is no specific susceptibility to tuberculosis Induced by asbestosls and be,Ilka ourselves. Is anxious to accumulate comparative statistics froa various parts of the world to establish the general clinical experience. 1 I % / <? # / (2) As Z Indicated In my Inst latter the Quebec experience is not yet analysed; there Is only an impression that most of the asbestos workers die of tuberculosis without taking into account the excessive prevalence of such Infecticn among the population of the Province. This impression needs aerification by careful analysis of morbidity and mortality statistics collected from the employees of the asbestos Industry, from their faailles not exposed to asbestos dust and froa other commualthe in the Province of Quebec. 8uch data should than be compered with similar statistics for asbestos workers in other countries. If there is a specific occupational predisposition to tuber culosis it will become apparent on aueh analywus lust as It has for silicosis. Wherever silicosis is being created, the high mortality from tuberculosis cannot be hidden. Z do not believe that there la much tuberculosis among asbestos workers In the Tnlted 8tates end suspect that the excess mortality from this cause in England is probably due to the low living standards of industrial workers. Possibly selection of eases coning to autopsy has influenced the picture. American studies have tins far failed to demonstrate enough tuberculosis among asbestos workers to cause comment. The U. 8. Public Health Service Study of Asbestosls in the Asbestos Textile Industry in Worth Carolina. (Bulletin 211). Issued in 1938. hardly mentioned tuberculosis, dismissing the subject with the statement - -age 51 that "there ware only 2 cases of active, pulmonary tuberculosla group* (511 employees). Shull. (Radiology 27. So. 3. 279-292x examined 71 of 100 eases discharged from the plants where the Health Service made its study 15 months later and found 8 cases complicated by tuberculosis of slight to moderate extent but only 2 were active. These two subsequently died of tbls cause and in 2 others the infection later became active. Shull states In his conclusions that asbestosls does not predispose to tuberculosis.* Presumably he infers, although he does not say so, that the A eases of active disease among 541 workmen represented accumulated disabilities when the ratal nation program was inaugurated. Donnelly (.T. Ind. Erg. and Tax. 18, Vo. 4, 222-228:1936) also enwined 151 discharged employees Inrknding the 100 reported by Shall. He gives .we details od the cases of tuberculosis* On- of them had worked ln~tbe asbestos industry for 5 month* and the otn-rs 15 months. The remaining 2 had worked 6 and 10 years respectively ar.l their infections night have been aggravated by exposure to asbestos dust. He points out, however, that an incidence of 2 cases among 151 industrial employees la no higher then In any other industrial group. VcPheeters, (J. Ind. Erg. and Tax., 18, 229-239: 1936) likewise ex amined and reported an these esses end he la in entire agreement with the other reporters. In his conclusions he states, *Vo activating or aggravating effect of asbestos dust or asbestosls or tuberculosis was observed.* finally I believe I told you that I myself, had Just re turned from Worth Carolina .where I had reviewed chest films of some 100 emoloyees of the local asbestos industry end sew <nly one that showed any lxsilcatloa of adult type pulmonary tuberculosla. This was completely i r Mr. Xvan Sabourls O) february 28, 1944 baaled. X eomaented on the fact to tho members of the Medical Board of tne State Industrial Commission with whoa X waa conferring and tha Chairman, In*. Taatal, told me that tuberculosis was a rare finding among asbestos workers although common enough In other Industrial workers In their state. It would therefore, appear that In forth Carolina ashestosls does not favor or predispose to tuberculosis X have Just now completed a review of 12? films for an asbestos fabricating plant in another state. In th .s plant the amount of severity of the asbestosls on the first examinst .on In 1930 was well marked, approximately 40Jt of the group showing definite X-ray evidence of the disease, levertheleas, tha total adult type tuberculosis rata was only 5%i four of these eases occurred In persons with asbestosls and 2 of them were considered probably active. A second or 'minatlon was made upon 67 of the original group after an Interval of f years during which they remained at work, low the Incidence of asbest'^ had Increased to 62 but the tuberculosis rate had fallen to 2.9J. 1 third examination was done on 57 of the original group who still remained In employment after a further Interval of 3 to 4 years; in this group the Incidence of esbestosls was over 60% but that for tuberculosis only 3*5> Xn spite of excessive amounts of severe asbestosls tha tuberculosis rate remained within tha Units usually found in American Industrial populations. The behavior of the tuberculosis In these people was not unusual. Tor exasple one man, a spinner for 13 yssrj, was 31 years old arhen first examined. Be had at that time an early non-specific dust reaction and evidence of old tuberculosis in the top of hie lungs. Xn two succeeding examinations his dust reaction steadily Increased to reaeh first stage aabestosls 9 years after he was first seen. Bis tuberculosis however, remained apparently unlnfluenced. Boat of the others behaved in the same manner. These people had already been exposed to asbestos dust for periods of 3 to 18 or more years when they were first examined and the three subsequent axa si nations during the following 9 years give us a good opportunity to follow what might have developed. Bo new ease of tuberculosis appeared. If It had not by that time the chances were not very great that they would later. After they left the asbestos industry we do not know what happened to most of then but on a few there are Insurance records that lallc&te the cause of death. Two died of tuberculosis. One had >ia his Infection when he was examined In 1930 at the age of 50. At that time be bad an early asbestosls after weaving for 10 years and ovldene# of associated chronic tuberculosis. Be sms advised to leave wnieh he did and died of his infection aboct 3 year* later. The second --n ntd 32 >d been a weaver for 12 years and bad first stage asbestosls but no evidence of tuberculosis at the time. Bo loft his Job after the Sr. Iran Sabourla (4) February 28, 1944 first examination tor tmiobi Dot etated. fhtoo years later be was reported to bare died of tuberculosis la a sanltorlua. Such cases could occur anywhere. Zt Is possible that if we had follow-ups on acre of these eases after the? left the asbestos Industry we would flrd aore persons who subsequently contracted tuberculosis and died of It. Srwever, tbs evidence now available Indicates no such tendency. Animal experiments, contrary to those upon silicosis, disclose no theoretical reasons for suspecting that asbestosls creates axgr special suscepti bility to the tubercle bacillus of Koch. Z am becoming more and more convinced that that the high tuberculosis rates reported In English autopsy statistics are due to causes other occupation. 1 believe that the same must hold true la Quebec where the amount of severity of the asbestos dust reaction is very much less than It Is In tba fabricating plants In the United States. Z believe Z have covered the other points raised In letter M'n* will therefore not prolong this discussion further. ery truly yours. Leroy U. Gardner, V. P. Director IDG:BH ce to Mr. Vandiver Bn