Document OE7OGxjXYR3XGOVMQ8w4v1VXw

m !( I J l MEMORAMPCM TO: J. A. Zapp, Jr FROM: 0. J. Stopps J Hoveaber 2, 194 TR2F REPORT Conference on Biological Effects of Asbestos hald Monday, Tuesday and Wednesday, Octobar 19, so and SI, 1964 undar tha auapleaa of the New York Acadaay of Sciences, the Saction of Bloloalcal and Madlcal Selancaa Although thia wai a well-conducted and well-attended aaating thara balng some thraa to four hundrad paraona praaant at almost every aaaaion, thara was alao a faallng that thara were aavaral ghoata praaant at tha banquat of information prtaantad. Ho doubt thia fooling largaly steamed from tha fact that out of aona 53 papara glvan, only two of thaa vara glvan by paopla eonnaetad with tha aabaatea Induatry in tha United State* and Canada, whereas thara war* savan givan by rapraaantatlvaa of tha aabaatoa Induatry In Britain and a further thraa or four papara ware givan by paraor.s ' eonnaetad with tha aabaatoa Induatry in South Africa. Fro* tha point of vlaw of tha Du Font Company aa a whola, tna main tntaraat of tha aaatlnga waa In drawing attention to tna fact that aabaatoala and complications of aabeatoala have now boon found in paraona who would not in tha ordinary way ecne to alnd as balng expoaed to aabaatoa; that la to aay, thay do not work in aabaatoa mlnea, aabaatoa mills, or aabaatoa textile faetorlea. Underlining thia relatively wide exposure of paraona to asbestos was tha work of I. J. Salikoff, froa tha Rt. Sinai Hospital, Hew York, who has bean studying tha workers la tha insulation trades in Hew York City. The investigation reported concerned 1593 members of the International Association of Heat and Frost Insulators and Aabaatoa Vorxars la tha Hew York-New Jersey metropolitan area. The study included avary individual who waa a mambor of this union on Decamber 31, 19*2, or who joined by December 31, 1962. Two hundred sixty-four man ware dead on January 1, 1963, and 43 have died since. Kaeh death was studied. One thousand two hundred fifty-eight sen were still alive and 1117 of theta were examined. Thia represents 89.90 of tha population at rlak. Clinical, radiological and pulmonary funetlon examinations ware also sada of thaaa sen. x-ray ranking of tha degree of aabaatoala praaant In four grades ranging from 0 to 3 Indicated that In those having 0 to 9 years of exposure to asbestos, 89.60 had no asbestosls praaant, while 360 had grade l. Whereat with 40 or more years of exposure, 94.20 had grada 2 afastesls and only 5.80 had none. In an analyala of 307 consecutive 0UF 0900291 a. -2.8 3 i2848* 1 DU 021688 death* saong asbestos insulation workers, 53 war* found to have eareinoBsaof th* lung, 9 had mesotheliomas of the pi aura, 35 had esreincmaa of th* gastrointestinal tract, and 27 had neoplasn* at ether site*; 17 of thaa had ssbestosis conflraad at autopsy. Tha conclusion of this paper was that pulmonary ssbestosis was a signlfleant risk of Insulation workers in the United States: -i it will be noted froa the above figures that this paper touched upon the point developed later by other workers at the Mt. Sinai * Hospital that the risk of earelnooa, either of tha raspiratory tract or of the csatrointestinal tract, appear* to b* significantly creator aaoncst the insulation workers than aaongst the general population. At a later session X. C. Hammond of the Mt. Sinai Hospital group further underlined the unusual occurrence of carcinomata aaongst the insulation workers. First of all he noted that in a prospaetive study of 235 consecutive deaths aaongst this group of insulation workers carried out over the years 19*3-1962 that the total nuaber of deaths were increased (observed 255. expeeted 20) as were deaths caused by cancer of lung and pleura (observed 45, expeeted 7), and atoaach and colon (observed 29, expected 10). Or. Haaaond then updated his information to Include a total of 307 eonseeutlv* deaths froa January 1, 1943. to August 30, 1964. this updating of his statistics did not aaterlally affect the standings but did serve to underline the fact that deaths due to lntraabdoalnal neoplasm* were also greatly Increased over what might have been expected if the death rates of the general population had prevailed. Or. Haaaond pointed out that for a variety of reasons the accuracy of diagnoses of gastrointestinal traet neoplasms is often insecure. In two-fifths of the 49 such deaths, analysis of all of the available data showed the diagnosis to be presuaptiv* only. This was especially true of stoaach cancer (8 out of 13) and generalised abdoalnal eaneer (6 of 7). Therefore it is possible that peritoneal aesotheliooa aay be even sore eoBsnon than the 5 out of 307 deaths reoorded. Zn addition to the neoplasia aaongst the recorded deaths, there were three sen alive with known neoplasms (1 lung eaneer, 1 pleural, and 1 peritonoal mesothelioma), as well as on* apparently cured of tongue eancsr, on* of eaneer of the eolon, and three following aueeeaaful resection of localised lung eaneer found in ehla survey. Zn question* at tn* and of this paper. Or. Haaaond brought out that tha group of workers had presuaably not boon sure intensively studied froa tn* pathologies! point of vlow than any other eloilar group of worker* in another industry sine* until tha publication of the results there had not been any particular cause for ooneorn that the asbestos insulation workers were showing in abnormal incidence of neoplasia. OUT 0900292 29487 DU 021689 1 -3- A report from Turner Brothers Asbestos Company, Ltd., Rochdale, England, and presented by Or. J. T. Xnox, snowed a somewhat more optimistic story when suitable dust prevention rsgulstions were Introduced and snforetd in the ssbsstos industry In s mortality study of workers In an asbestos factory carried ou* prior to the enforcement of the British Asbestos Industry Rsgule-' tlons excess mortality amongst workers employed for 20 years and upwards was observed. Lung eaneer In association with asbestosts was responsible for a considerable proportion of this excess, a study of a group of workers from the same factory exposed since the regulations went into offset shows a reduction In mortality rate without an exeess of lung eaneer. Or. Hammond had pointed out In his paper that the extreme rarity of pleural mesothelioma in tne general population meant the finding of even a very few cases ir. a particular study in industry was highly significant. Or. t. C. limes of Belfast, Ireland, tackled the problem of mesothelioma from another point of view. He had studied 42 eases of pleural mesothelioma found in his department In Belfast over the past 14 years; the population at risk being about three'quarters of a million people. A positive history of exposure to asbestos at work was obtained In 32 of the easea compared with only 9 of 42 matched controls. Asbestos bodies were found in the lungs of 88ff of patients with mesothelioma of the pleura, 30% of patients with carcinoma of the bronchus and 20.SB of patients dying of nonmalignant disease. The frequency of finding of asbestoe bodies in the lung Is higher (27B) in men dying of non'mallgnant disease between 60 and 69 years of age who went Into Industry between 1905 and 1915 than la the 50 to 59 age group who started work between 1915 and 1925* Between 1906 and 1923 over 1000 tons a year of boiler composition were iaoerted Into Belfast compared with 600 tons a year at other times. This boiler composition was an Insulat ing material containing a considerable proportion of asbestos fiber. Or. Slaea pointed out that tha latent period for the development of pleural malignancy after exposure may be up to forty years so that increasing numbers of eases arising from exposure can be expected for many yoara to camo. Or. Wegner, of the M.ft.C. Pneumoconiosis Research Onlt, Glamorgan, Wales, British Sales, noted that an association between aabestoa and pulmonary malignancy was now gantrally aeespted. More recent Investigation had shown that there was an increased incidence of pleural and peritoneal mesotheliomas occurring in people oeeupatlonelly or environmentally exceed to asbestoe duet. Zn some of these eases the exposure has been extremely slight and not sufficient to produet the histological features of asbestosis. 1ha only pathological avldance of exposure has been the presence of asbestoe bodies er fiber* in tne air spaces. In South Africa more than 100 eases of this tumor have been confirmed histologically. DUP 0900293 DU 021690 1 Marly all of these eaata have been eonflned to ona asbestos mining araa. The majority of these poopla vara not employed in the asbestos manufacturing Industry. Chemical investigations hava shewn that oils containing earclnoganle hydrocarbons art present naturally m this particular typo of asbestos. Another study taking such tha same approach as that reported by Dr. Haas of Belfast was reported by Muriel Newhouse of the London School of Hygiene and Tropleal Medicine. Sr. Newhouse reported or. a series of patients attending a large hospital in the east end of London. Or. Newhouse's patients were divided into two groups; the first consisted of 8; patients In whoa the diagnosis of mesothelioma had been confirmed at autopsy or by biopsy. Zn all but seven the past occupational and domestic histories were obtained In 21 patients the tumor was peritoneal In origin and in 62 it was pleural. The earliest recorded death was 1917 but only ten of the series died before 1950; 550 of the males and *2* of the females died under the age of 55. The interval between the first exposure and development of terminal Illness ranged between 16 and 55 years, the mean was 37. The second group consisted of 76 patients at the same hospital, matched by sex and date of birth with those traced In the first series; 52.6# of those suffering from mesothelioma had been exposed to asbestoe as compared to 11.8m of the control group. Three main types of exposure were recognised; work In factories manufacturing .asbestos textiles, insulating materials and other products, employment as laggers or insulators, and exposure to dust* brought home by relatives working with asbestos, eighteen of those employed In factory work or whose relatives were working with asbestos were smployed In one factory. This factory opened m 1915 and was until recant years a heavy user of erocidollte. All those whose records eould be traced worked with this type of asbestos. Amongst the 36 patients with mesothellomata with no positive occupational history and no relatives living at home working with asbestos, there were 11 *eo lived within half a alls of an asbestos factory, rive of the control series also lived in the same area. The difference in the proportion of patients in the two series was statistically significant. Or. Ian Webster, of the Pneumoconiosis hesearch unit, Johannesburg, South Africa, pointed cut in his paper that although animal experiments have succeeded in showing the growth of a mesothelioma-like tumor in animals in which the asbestos was Inoculated directly into the pleura, it had not been possible to produee carcinomata by exposing the animals to an asbestos dust cloud. 'A further study of pleural mesothelial tumors from autopsy records was given by W. 01yn Owen, of Liverpool, Ingland. Seven teen eases were selected as good examples of diffuse mesotheliomas. Sixteen of these 'were pleural and one was peritoneal. Ivldenee of asbestos exposure was obtained in lb (820} of the 17 mesothelioma OOP 0900294 Z29489 DU 021691 -5- eases. Kona of a similar number of subjects with cane*ra of *nar altaa wara Known to have handled aabaatoa. Of thoaa giving an occupational history of aabaatoa exposure, five wara loggers employed by flma of insulation engineers and two wara boiler maKara (shipbuilding), two patlanta wara employed by aaeKwara manufacturers and had handlad old aasKa which had contained aabaatoa. Only two of the 17 patlanta had worked In aabaatoa faetorlaa, and ona patient gave a hietory of close environmental axpoaura having worked in the offices of concrete manufacturers using asbestos cement. Or. William 0. Buchanan, Ministry of Labour, London, pointed cut that earlier atudiaa of the British Vital Statistics records Indicated an apparent association between the presence of asbastosis and the finding of a thoraeie tumor; although such an association had bean postulated tone years before 19*7, it was believed that the study reported in that year was the first occasion when these findings had been related to a sizable group. The proportions so affeetea appear to be increasing in more recent studies. Up to the end of 19$3, So* death certificates recording the presence of asbestosls have been obtained and annual totals of such certificates were currently increasing. The proportion also recording a thoracic tumor has also In both sexes continued to Increase disproportionately eo the total number so that currently over 50% of the males dying with asbestosls present have also a neoplasm, gven when viewed against the steadily rising incidence of lung eaneer in the population as a whole, fir. Buchanan felt that there was little doubt that this increase was a real one. Sr. Bader presented an interesting series of 17 eases of employees actively working in an asbestos factory ten years ago at whleh tips the plant in which the sen were employed discontinued operation. ie men have been followed since that time with serial clinical, radiological and pulmonary function investigations. During tha baseline studies, pulmonary function examinations, when abnonal, revealed the classic findings of the alveolar capillary block syndrome, uniform decrease in lung volumes, well-preserved maximum breathing capacity, decreased arterial oxygen saturation (especially on exercise), normal pC0a values, and decreased diffusing capacity. Hyperventilation at rest and exarcise occurred in more than half the eases, and dead spaee ventilation and alveolar ventilation were increased. The aost sensitive index of Impaired function was arterial oxygen saturation. Slight reduction at rest was found in six, and reduction below 98% was found in half of ths wortten on exsreise. The post-employment serial evaluations werejsade in tezas of x-ray progression, development or worsening of dyspnea on exertion and further measureaents of pulmonary func tion. Follow-up observations were limited by complications of the disease being studied. Of the 17 men studied ten years age, 8 men are now dead;- 8 of lung cancer, 1 of pleural aesotheliema, 3 cf gastrle carcinoma, and 3 of pulmonary asbestosls (core pulmonale). U* 0900295 129499 1 DU 021692 6 and 1 of myocardial infarction. Nino of the original woricnen art till allVt( on# following tn# rtatetion of a lung or lung eancor. Two paptra woro presented by workers from Britain Uacuaiir.c tho valut of routlno lung function studies, In tho first, Ross Hunt, of Brltlah Bolting and Aaboatoa, Ltd., Yorkshire, Ingland, gavo tho roaulta of routlno lung function atudlca on 815 Bployooa in an aaboatoa proeoaalng factory. Boutins work in cnia field of lung function waa atartod in July i960 In an aaboatoa textile plant In tha north of Zngland. Tho ala waa to ertato a att of normal flgurta for lung compartment valuta, gaa tranafar factor eoafflelanta, 90% mixing lndlcta, ventilation on exorcise, and forced breathing capacltlea. Tho subjects uaod In theao tests wore volunteers of both saxas In varying ago and atature groups from departments other than cheat proeoaalng aaboatoa. Theao roaulta wore then analyaad statistically and the regression formulae obtained applied to the roaulta of man and women working in those occupations exposed to asbestos. Pulmonary function tests were also used aa a screen to prevent people with lung Impairment from talcing up work in departments where asbestos dust waa prevalent. Some difficulties ware encountered in tha beginning both In subject responae and sampling technique. But these were overeeme and this paper deals in the main with the technique and results obtained over the past three years. The evidence points to a significant decrease In gas transfer and vital eapaelty before any radiological or clinical signs are evident. The other paper given by M. L. Thomson and W. J. Smlther, from the London School of Hygiene and Tropleal Medicine and from Cape Insulation and Asbestos Products, Ltd., London, Sngland, indicated that inspiratory eapaelty and vital capacity were the best discriminates of asbestosls amongst the many pulmonary function tests used. Zt would appear from the ooneenaua at this meeting that the risk of persons noe normally thought of as engaged in work wien asbestos, and certainly not thought of as being in the asbestos Industry, la greater than waa originally thought. This fact should bo berna in mind and ombraeoa not only the perton'e oeeupaeion tut else his hobbles - for lnatanee, a do-it-yourself worker at home can have a material expoaure to aaboatoa during heme insulation. Sines tha prognosis for a diagnosed pleural mesothelioma is extremely poor, varying from a few weeks to one year, It is important that no parsons within thd company should be exposed to asbestos whether as frank asbestos fiber or asbestos contained in sueh materials as insulation, lagging, asbestos cement, ete. Zt is also of eourse Important to present this type of information in porepeetlve and not to cause undue alarm smea there it no reason to believe that good Industrial hygiene practice sueh as the- use of masks whan cutting asbestos or using pewdsred or fibrous asbsstos products it not completely affective in preventing later disease, it la whether L -L5'< `>491 OUP 0900296 DU 021693 -4 1 -7or not aabeatoa fiber penetrate* through tha reaplratary ptsaac** that natter* and not tha claaalfleation of tha man'a occupation. Per paraona who would lilt* aora Information on thla topic, tha abatraeta of tha Conftranca on tha Blologleal Iffacta of Aabeatoa art available froa tha writer and it la expected that the proceeding* of the conference will be publlahad within tha year. WS/dyb Out 0900297 129492 DU 021694