Document 6RgDoG6KaeD3e18X9XJnjJMrE

V1- .1 j . fatanary 28, 1944* PLAINTIFFS EXHIBIT Canada Daar Mr* Sabourini Z have your letter of ^hwnw 22^asking for eoaaanta on -- the relationship between asbastosla and susceptibility to tuberculosis* This question cannot be answered decisively fron a study of post aorten notarial alone* Medical problens of this nature are usually solred on the basis of probabilities and it is this setter of probabilities on which we need further evidence In the ease of tuberculosis associated with asbastosla* Merewether in his *Menoraadun on Asbastosla* Tubercle Movenber and December, 1933 and January, 1931) adnits that *the data on the subject are neager** Be reports that of 374 workers while at work, only 4 showed signs of active tuberculosis and that the British Silicosis and Asbestos Medical Board in its first periodic erawiwatlon of workers in this industry found only one ease of asbeatosle and tuberculosis la 11912 ezanlnations* On the other hand the ltagllsh post sortan notarial 7 at that tine revealed 35*73 of the eases conplieated by tuberculosis* 1 (Subsequently he appears to have found sore cases if Dr* Middell is cor* reetly infomad)* m the publication cited Merewether ecncludesi The evidence therefore* points to the hypothesis that at present the added risk to Mbestos workers fray rlMrw tubeweninaia is United and definitely leas than in workers exposed to free aillesj virulent nas* sive infections will aa in the general pupulatlen, cause deathf leaser ones will result in wore widespread fibrosis than would appear in eases anongst the general population and alight infections, in nrwann with naay I other aaffections, are likely to precipitate death in' fieaees of asbostosis where they wouldn't do 1 in the general population** the underscoring is nine tut I agree with these views* When Dr. Merewether was in this country last year he visited ne for several days and we spent uost of our tine discussing tboee probl j Be still accepts our axperlnental work which proves that there' Is/ no ' specific susceptibility to tuberculosis induced by asbestosls and) he,like fr ourselves, is anxious to aeeunulate ooaparatlve statistics fron vUrlCUS {(parts of the world to establish the general clinical experience*' 070$ (2) As I indicated in my last letter the Quebec tgariyce is not yet analysed; there is only an impression that post prjthe : asbestos workers die of tuberculosis without taking into account the : excessive pmtlsw of such infection' among this' population of the 1 province- Thu: Impression needs verification by careful analysis of Morbidity and Mortality statistics collected froM the employees of the asbestos industry, fron their families not exposed to asbestos dust and froa other eoamuttfttfcm in the Province of Quebec. 8uch data should than be compared with similar statistics for asbestos workers in other countries. If there Is e specific occupational predisposition to tuber* colosls it will becone apparent on auch analysus just as it has for silicosis. Wherever silicosis is being created, the high Mortality froM tuberculosis cannot be hidden. -- I do not believe that there is auch tuberculosis I asbestos workers In the United States and suspect that the excess Mortality / from this cause in Wwgimd is probably due to the low living standards of Industrial workers. Possibly selection of cases Coming to autopsy lias influenced the picture. Aaerlcan studies have this far failed to denonstrate enough tuberculosis aaong asbestos workers to cause eanait. The U. 6. Public Health Service Study of Asbestosls in the Asbeatoa Textile Industry in Horth Carolina, (Bulletin 241), issued in 1938, hardly Mentioned tuberculoala, dismissing the subject with the statement on page 51 that "there were only 2 cases of active, pulmonary tuberculosis in thn group" (541 employees). ohull, (Radiology 27, Ho. 3, 279-292* 193.6) examined 71 of 100 eaaes discharged from the plants where tbs Public Health Service made Its study 15 months later and found 8 caeca complicated by tuberculosis of slight to moderate extent but only 2 were active. These two subsequently died of this cause end in 2 others tbs 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 4 cases of active disease among 541 workmen represented accumulated disabilities whan the examination - program wee inaugurated- Donnelly (J. Ind. Byg. and Tax. 18, Bo. 4, 222-228*1938) also examined 151 discharged employees Indnding the 100 reported by Shull. He gives more details on the esses of tuberculosis* One of then had worked in the asbestos industry for 5 months and the others 15 months. The remaining 2 had worked 6 and 10 years respectively *ad^th*ir *ftions might have been aggravated by exposure to asbestos dust. He points oat, however, that an incidence of 2 cases 151 industrial employees is no higher than In any other industrial group. ePheeters, (J. lad. Hyg. end Tox., 18, 229-239* 1938) likewise ex- amlncd and reported on these eases and he is in entire agreement with the other reporters. In his conclusions he states, "Bo activating or aggravating affect of asbestos dust or asbestosls or tuberculosis was observed." Finally I believe Z told you that I myself, had just re turned froa Horth Carolina where I had reviewed chest films of boss loo employees of the local asbestos industry and saw only one that shewed any indication of adult type pulmonary tuberculoala. This was ooapletely 0705 Mr* Ivan Sabouria (3) February 28, 1944 healed. I commented on tha fact to the members of the Medical Board of tha State Industrial Commission with whoa I was conferring and tha Chairman, Dr. TeSSml, told as that tubareulosls was a rara finding among asbastos workers although common anough in othar industrial workers in thalr stata. It would tharafora, appear that in Worth Carolina asbastosls doas not fawor or pradisposa to tubareulosls. I haws just now completed a resriew of 12$ films for an asbestos fabricating plant in another stata. In this plant tha amount of severity of the asbastosls on tha first ayarn! nation in 1930 was wall marked, approximately 40 of tha group showing definite X-ray evidence of the disease, levertheless, the total adult type tuberculosis rate was only four of these oases occurred in parsons with asbastosls and 2 of them ware considered probably active. A second examination was made upon 67 of tha original group after an interval of $ years during which they remained at work. How the Incidence of asbestos had increased to 62J( but the tuberculosis rate had fallen to 2.9. A 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 tha incidence of esbestosla was over SOJt but that for tuberculosis only 3.$. In spite of excessive amounts of severe asbastosls the tuberculosis rate remained within tha limits usually found in American industrial populations. The behavior of the tuberculosis in these people was not unusual. For example one man, s spinner for 13 years, was 31 ysara old when first examined. He had at that time an early non-specific dust reaction and evidence of old tuberculosis in the top of his lungs. In two succeeding examinations his dust reaction steadily increased to reach first stage asbestosls 9 years after he was first seen. His tuberculosis however, remained apparently uninfluenced. Host of the others bshavsd 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 end the three subsequent examinations during the following 9 years give us a good opportunity to follow what might have developed. Ho new case 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 them but on a few there are Insurance records that indicate the cause of death. Two died of tuberculosis. 0ns had had his infection when he was examined in 1930 at the ege of 50. At that time he had an early asbestosls after weaving for 10 years and evidence of associated chronic tuberculosis. He was advised to leave which he did and died of hla infection about 3 years later. The second man aged 32 had been a weaver for 12 years and had first stage asbestosls but no evidence of tuberculosis at the time. He left his job after the 0706 Hr. Ivan Sabourln u> ,February 28 1944 first examination for reasons not stated. Three years later he was reported to have disci of tabereulosis in s ssnltoriun. Such cssss could occur anjnffiere.-- It is possible that if we had follow-ups on more of these eases after they left the asbestos industry we would find more persona who subsequently contracted tuberculosis and died of it. How ever, the evidence now available indicates no such tendency. texperiments, contrary to those upon silicosis, disclose no theoretical /reasons for suspecting that asbestosis creates any special ausceptlfbility to the tubercle bacillus of Koch. 1 am becoming more and more convinced that that the . high tuberculosis rates reported in English autopsy statistics are due I rto causes other than occupation. I believe that the sane must hold l true in Quebec where the amount of severity of the asbestos dust reaction !ils very much less than it is in ths fabricating plants in the United 'States. I believe Z have covered the other points raised In your letter and will therefore not prolong this discussion further. Tery truly yours. Leroy U. Gardner, M. D. Director LUOtRH ec to Mr. Vandiver Brown CTO 7