Document KJgVzmgQ1D4brbz8gr0Lj2qKK

?...-*./L.wy--------- ----------------------------------------------- .. i. development of aminations the Pnouw entrants are suitable at should be asked is *r? In our experience ns have been made in :at some can do. others j given by Merewethcr >sure was sufficient to >he lives long enough.** .rtmental Committee on >f Evidence, Appendices cts of Asbestos Dust on ustry. H. M. Stationery is) / 1930. 1031 VTHE OCCURRENCE OF ASBESTOSIS AMONG INSULATION WORKERS IN THE UNITED STATES* I. j. Selikoff, J. Churg, E. C. Hammond Section on Environmental Health, The Mount Sinai Hospital, Hew York, tfjf. Information currently available concerning asbestosis has beeri'derlT largely from studies of employees of asbestos textile factories and should properly be referred to such individuals. It is inadequate to speak now of "asbestos workers." With the growth of asbestos utilization, inchfoin^ rapid multiplication of the number and variety of itr'applications. i(wpdfd per haps be more accurate to categorize workman exposed to^s >estosJas "as bestos textile workers," "asbestos insulation workers," *asb< stos miners," "asbestos mill workers," "asbestos-cement workers," fcte. Th different oc cupations vary widely in important respects; in intimacy, intensity and duration of exposure, in variety/And grade of asbestks usee, in working conditions, in concomitant exposure to other dusts orynhalants. The ira portance of this distinetion/and the parallel obligation to evaluate and study the experience of aSoestos exposure/ii other trades, is emphasized by the fact that asbestp^ textile OTi rs drp nqw a minority of lose ex- posed during the inddstria* us of be^to; There were good' reasons $6r th^ exrfs emphasis on tos textile workers. The first cases of lestosisV e in textile workers.1'1 Fallowing the republieation pf Cooke* '1927,* with its rapid confirmation by the report of another case by S the FactorjrDepartment in Great Britain bad to decide whether tl^se were exceptional occurrences or repre sented a significantV.ealth risk^in industry. Accordingly, an investigation into the problem wasWndertaken during 122 and 1929." The scope of the study had to be restrfoed. Thy'teXrrir'Industry was selected for study since only here was theresRurg/or almost pure asbestos exposure. Since it was urgent to investigate -the effect of this dust, limiting the investigation to this branch of the industry avoided the possible complications which might be introduced by the presence of other potentially fibrogenic dusts. Moreover, in other asbestos trades, there were varying portions of asbestos in the dust to which workers were exposed, which would have added an other complicating factor. It was accepted that there were considerable numbers of workers exposed to mixed dusts whose risk would not be docu mented by study of the asbestos textile industry. Subsequent surveys, similarly designed to study the risk of industrial asbestos exposure, were also largely confined to asbestos textile works7*" This study Tork. supported by the Health Research Council of the City of New 139 llion su/fid*nt!v ation of the <,. narjy of thr Uv with external :t of proJongH s been a*he?.t<w Britain in U7l'nning 10 year* g asbestos frmi lS66.''Ash-sti> i other ashoto* ies. Commerml : least in 1874.*' besrosis in the s. Neither Panvhich the work* iciaj claim hr 027 and. again. ulaiion worker. -^t( eport of . or insula* jeux in Franee se'as insulation n workers %va> jund only thre** ering of naval er cent of tho.-* e trade and. a> ;mited to study misleading. i j j 1 first used as an IS70. Magnesia mg. made with i materials are :es was formed lights of Labor Selikoff ft al.: Asbostosis Among Insulation Workers 141 (predecessor of the American Federation of Labor), as "The Salamander Association of Boiler and Pipe Fetters."** In 1910, the present union of insulation workers in this country was chartered by the A. F. of L., as the International Association of Heat and Frost insulators and Asbestos Work* rn*. with the amalgamation of the Salamanders' Association of New York and other independent locals through the country.3' The members of this union are insulation workers, primarily employed in the building trades doing construction insulation work but also employed as insulation workers in shipyards and powerhouse construction and repair. Much of their work fo in the open air but it sometimes is, as aboard ship, in rather tight quar* ters with poor ventilation. The men generally work at all parts of the trade; few are specialists at one part of it or limit themselves to one material. Conditions of work vary from job to job and from company to company. Among the 1,117 men we have examined (see below), fewer than nine per cent of those with 20 years of work experience or more had worked for one employer primarily--even after four years of work ex* perience less than half had remained with their original employer. Review of work practices with insulation workers from various parts of the United States and with knowledgeable officials of the union and insulation em ployers indicates that techniques, materials and practices are rather the same through the country. Similarly, data published concerning the work practices in other countries2* suggest that asbestos exposure in insulation work is approximately the same the world over. . The asbestos exposure to which insulation workers are subject is limited and intermittent. Some cf the materials used contain no asbestos. Seventy- five years ago, the magnesia pipe'coverings had shredded rope as a binder, with no asbestos. Later, much work was undertaken with hair-felt, wool- felt. cork, rock-wool. In the past three decades, fibrous glass products have come into increasing use and these have been supplemented recently with foamed and expanded plastics for certain applications. Of the asbestos- containing products which are widely used by these men. magnesia block insulation was and remains perhaps the most important. This usually con tains approximately 15 per cent asbestos. While asbestos cement has a varying asbestos contest depending upon its manufacture, it also generally has 15-20 per cent or less of asbestos. Asbestos paper products such as air-cell have a higher asbestos content but are used in much smaller quantities. We have studied the insulation materials with which these men worked in the past, in several ways. First, review of old trade and technical pub lications from the early part of the century to about 193035 indicates that the major asbestos-containing materials have remained about the same, especially insofar as the amount and nature of the asbestos content is con cerned. As expected from knowledge of sources of U. S. imports of as- ' fl\ j*. $ F 142 """ ` `Annals New York Academy of Sciences - bestos, cfcrysotile asbestos was largely used.'5 This has been confirmed by analyses of magnesia block obtained during repair work. In later speci mens so obtained, crocidolite has also been found. Moreover, materials used for ship insulation, while containing the same amounts of asbestos as above, began is 1934 to have significant amounts of amosite in addition to chrysotile, because of the lighter weight of the material.9 Man* has recently brought shipyard insulation experience up to date, comparing it with the observations of Fleischer and colleagues,9 and concludes that .. insula tion materials and work methods have remained essentially the same" since 194S. 'Measurement of dust exposures of insulation workers have been but in frequently reported and have been hampered by the varied nature of the work. As is other asbestos work, peak counts are met which are exces sively high but generally counts for asbestos fibers have been within the five rappef. M.P.C. of the A.C.G.I.H.9 ** Such counts as have been available, made during work engaged in by the men studied by us. have shown a range similar to that of published counts.4* Present Investigation We undertook to.study the question whether asbestos exposure during insulation work in the U. S. was associated with the hazard of asbestosis and its complications. Our investigations have been concerned with the 1522 members of the insulation workers union in the New York (Local 125Netr Jersey (Local 32) metropolitan area. The New York Local of the Union is a direct lineal descendant of the Salamanders' Association, and is the oldest Union of insuiation workers in the U. S. The 1522 men studied by us include all members of these Locals from 1942 to 1962. On December 31. 1942, there were S32 members and $30 men subsequently joined be tween 1942 and December 31. 1962. This includes every man who was a member of either of these locals at any time in this period, whether or not he remained in the trade as an insuiation worker. It is believed that the experience of these men fairly represents a cross section of the experience of insulation workers during the history of this trade in the U. S. Records of the union indicate that these locals had 335 members in 1914 and that 1738 members were admitted to these locals from 1915 to 1963. la the United States as a whole, the Insulation Workers Union in 1914 had 1487 members and 2S.338 were admitted from 1915 to 1963. The adequacy of our sample can be gauged by reference to these figures (see Table 1). However, our data does not include information concerning nonunion in sulation workers, maintenance insulation workers, insulation work as part of other trades or undertaken by insulation workers in other unions. The number of men involved in insulation work in these areas is not known to us. 152 Annals New York Academy of Sciences of both the pleura and peritoneum. A lung cancer has also been reported in a workman in a factory making asbestos insulation.33 However, these reports, while interesting and valuable, could not establish an association between the two conditions. It is possible that additional lung cancers and mesotheliomas have occurred and may even have been reported but such reports do not state the nature of the asbestos exposure and such instances may be included among cancers in "asbestos workers.'* Our experience that the lapsed period from onset of exposure is gener ally prolonged before the appearance of lung cancers in asbestos insulation workers coincides with the general experience of long "latent periods'' in such cases. Indeed, in the infrequent cases in which very short periods hare elapsed from onset of exposure, it might well be that the lung cancer found is coincidental. Such long latent periods would correspond to simi larly prolonged periods associated with lung eancer in chromate workers.34 nickel*3 cancers, arsenical lung cancers-** and the increased incidence of lung cancer among regular cigarette smokers.'7 In Doll's series/7 a long latent period was noted in all cases. Neoplasms have also bees reported among individuals indirectly exposed to asbestos insulation work, as carpenters,* steam fitters,3-' and other building trade workers/* . Summary An investigation involving 1522 asbestos insulation workers in the New* York-New Jersey metropolitan area has been conducted. Among 392 in dividuals examined more than 20 years from onset of exposure, radiologi cal evidence of asbestosis was found in 339. Is half of these, the asbestosis was moderate or extensive. In individuals with less than 20 years of exposure, radiological evidence of asbestosis was less frequent and when present, much less likely to be extensive. Neoplastic complications of asbestos exposure were studied among 307 consecutive deaths in this group of men. Lung cancer was found to be at least seven times as common as expected and cancer of the gastrointes tinal tract three times as common as expected. There were 10 instances of mesothelioma of the pleura or peritoneum. Of the 1258 men alive at the start of this survey, 1117 were examined. Eleven cancers of the lung or pleura were found during this survey of the living members, all among the 392- men with more than 20 years from onset of exposure. No cancers were found in those men. the onset of whose work experience was less than 20 years. We may conclude that asbestosis and its complications are significant hazards among insulation workers in the United States at this time.