Document 4a2r7O6qq85b3jGK0NQEMrZeN

Asbestos-associated Disease in United States Shipyards Irving J. Sc-iikoff, M.D. and E. Cuylsr Hammond, Sc.D. - RECEIVED MAY 12 1978 s. K. RHEE CLINICAL LATENCY OF ASBESTOS-ASSOCIATED CANCER During lire past 15 years ihe important disease potential of asbestos exposure has been clarified. The pi incipal hazards have been demonstrated to be cancer of a num ber of sites, and asbestosis. Among asbes tos workers, approximately 20 percent of all deaths are clue to lung cancer, six peiccnl or seven percent to pleural and/or peritoneal mesothelioma, and there is an excess found in several other categories (e.g., cancer of tire esophagus, stomach, colon-rectum, oropharynx, larynx, kid ney). Table 1 provides gn analysis of causes of death among 17,800 asbestos insula tion workers in the'-United States and Canada followed prospectively from January 1, 1967 to January 1, 1977. Risk of asbestos-associated disease has also been observed in workers in other trades where asbestos exposure occurs-- Dr Selikoff is Professor of Medicine, and Director, Environmental Sciences Laboratory, Mount Sinai School of Medicine, City Univer sity of New York, New York, New.York. Dr. Hammond is Vice President, Epidemiology and Statistics, American Cancer Society, Inc., New Yoik, New York. This is a special report from the Environmental Cancer Research Piojeel, American Cancer Society and the Environmental Sciences Lab oratory of the Mount Sinai School of Medicine of the City University of New York. for example, where individuals simply working near "asbestos workers" are ex posed to the same dusts. Risk extends even , to individuals not employed in an asbes tos-contaminated environment; mesothe lioma has been found among family con tacts of asbestos workers residing in the same households, as well as among people living within a quarter of a mile or so of asbestos plants or other facilities which have used asbestos-containing materials. Although mesothelioma is not neces sarily the most common disease resulting from asbestos exposure, it provides a very useful index of such problems, since it is only uncommonly seen as a result of ex posure to other agents or without iden tified cause. Large stale investigations of series of cases of mesothelioma in France, Great Britain, the Netherlands1-3 tfnd else where have demonstrated that the large majority of these cases can be traced to prior asbestos exposure. For these neoplasms, as for all can cers due to asbestos exposure (and, in deed, for extensive asbestosis as well), a rather uniform characteristic has been found; the disease usually does not be come clinically evident for 15, 25, 35 or more years from onset of asbestos ex posure. The initial decades are periods of grace with no illness or disability. While some early X-ray changes may be seen after five to IS years, they are limited in extent and nc-t usually accompanied by significant symptoms. They merely dern- VOL 28. NO. 2 MARCH/APRtt 1970 67 HWBUI0002780 TACLE 1 Deaths among 17,800 asbestos insulation wo rkt'! in the United States and Cantda January 1, 1967-January 1, 1277 Number of men Man-years of observation 17,800 106.855 Total deaths, all'causes Total cancer, at! sues Lung cancer Pleura! mcsc:-e ie~i Peritonea! ne .oma Cancer of rsccnac.s Cancer ot s;c--.ec- Cancer of cc.cn-rer'.jrr. Ail other canes' Asbestosis Alt other causes Expected* 1.CG0.96 3'9.90 105.97 . t 7.01 14.23 37.86 154.83 1.351.00 Observed 2.270 994 . 45 66 tes 18 22 59 225 62 1.114 * fc ypeclccJ otat-s a't rase*j upon white male ager spocilic mortality csta c* trie U.S. National Centa* for Health Statistics lor 19G7- 1975 ana e* irzoo'c.' on ic 1976. . . * * Thes9 ere rare causes cf death in tho general population. The membership of tn* international Association of Heat end Frost Insulators and Asbestos Worse's a r _ CiO. ClC. was enrolled on January 1. 1967, &r.c has been Observed since onsiraic (hai enough asbestos exposure has occurred to produce such, changes. In this sense, they are harbingers of future risk of clinical disease. Tables 2-5 illustrate the characteristic latency of asbestos disease. In one group of 1,117 asbestos insulation workers in the New York metropolitan area, most of 725 workers with less than 20 years from on set of exposure (Table 2) had norma) Xrays. When changes were present, they were minimal in extent. On the other hand, after the 20-year point, most X-rays were found to be abnormal, frequently exten sively so.4Tables 3-5 show that few meso theliomas and little excess cancer of the lung occurred less than 20 years from on set. Most occurred 30 or more years from, onset of exposure. A young man may be gin work at the age of 18; his risk of as bestos-associated cancer does not become substantial until he is 40,.50 or older. EARLY STUDIES: MESOTHELIOMA IN SHIPYARDS In 1968, the first warning that asbestos 68 CA-A CANCFR JOURNAL FOR CLINICIANS Onset ot exposure (Vrs) 40+ 30-39 20-29 10-19 0-9 % TABLE 2 X-ray changes in asbesios insulation workers Mo. 121 iS-i 77 279 34 % Normal 5.8 12.9 27.2 55.9 89.6 *9 Abnormal 94.2 87.1 72.8 44.1 10.4 Asbestos*? te-a: L- 1 3 35 x * 28 102 4 9 18 36 j 7 4 158 c 0 26 0 0 Total 1.117 51.5 42.5 3CC *70 60 disease might be a serious problem in shipyards was sounded by HarricsMn Great Britain and Stumphius6in the Neth erlands when they reported instances of mesothelioma among shipyard workers. What was worrisome was that the men were not "asbestos workers" but rather, individuals employed in other trades. At the Dcvonporl shipyard of the Royal Navy, for example, mesothelioma in a boilermaker, a fitter, a shipwright, a weld er and a laborer were described. This raised the important question of whether asbestos use in shipyards might result in the exposure of the workers em ployed in many trades, to dust derived from the few "asbestos workers" in their midst. In 1943, in the United States, for example, approximately one in 500 ship yard workers was an insulator. The other 499 included welders, sh'pfittcrs, machin ists, pipefitters, electricians, boilermakers and painters (Table 6). The significance of this question is made apparent by the fact that dtiting World War II, approximately 4,500,000 men and women worked in our shipyards, many of them under conditions in which expo^u; to asbestos was possible. After World War II the total number of shipyard workers rapidly decreased from a high of 1.700,000 in the last months of 1943 to 200,000 or so. During the period of 1940-1976, total employment remained in this range, fluctuating with economic conditions and the country's shipbuilding program. The 200,000-250,000 figure characterized the total number in the yards at one time; however, there was much turnover, and the total number of difl'eient individuals was much larger. There are no accurate data readily avail able which could tell us how many differ ent people -- carpenters, riggers, electri cians, draftsmen, welders, etc. -- were so employed. Nevertheless, the early obser vations (soon augmented by later stud ies78) pointed to a pcfcentially serious problem. Harries has recently published his fur ther observations at Devonport, through 1973.'By the end of the year, he had ob served 55 cases of mesothelioma in that shipyard alone. Again, trades other than "asbesios workers" gave evidence of the hazard. Only two of the 55 worked directly with asbestos dagger, sprayer). The other 53 included 14 shipwrights, nine boiler makers, eight fitters and tight electricians (Table 7). John F.ogc of High Carley Hospital has published similar data from shipyards in Barrow (Table S)10; his most recent observation > are particularly disturbing.11 In Barrow, 429 individuals were seen, be- VOL 28. NO 2 MARCH APRIL 1978 89 TABLE. 3 Deaths among 17.800 asbestos insulation workers in the United States and Canada January 1, 19G7-January 1, 1977' Analysis by duration from onset of employment Total men Man-years of observation ` 12,633 89,466 Before 20 years from onset 12.C51 77.339 20 O' more years from onset Expactod* Observed Expected* Observed Total deaths, all causes 283.93 324 1.377.01 1,946 Cancer, all sites 42.65 83 277.25 911 Lung cancer Pleural mesothelioma Peritoneal mesothelioma Cancer ot esophagus Cancer ot stomach Cancer of colon-rectum 12.03 0.66 1.56 4.07 36 ^* 3 i i 4 93.94 6.35 12.67 33.79 449 64 10S 17 21 55 Asbastosis ** 8-- 154 xpccted deaths are casco upon white mole ege specific mortality data of the U.S. National Center for Health Statistics lor 1967-1975 and extrapolation to 1976, These are rare causes of death in the general population. tween 1964 and 1971, wilh radiologically evident pleural plaques; these plaques were considered to signal prior shipyard employment. Controls were429 men from a neighboring city (Carlisle), matched for age and date of X-ray; they had no plaques on their roentgenograms. Both groups were observed through 1976, i.e., for a minimum of five years. Among the 429 men with pleural plaques, there were 127 deaths; those with no plaques suffered 74 deaths. The excels was primarily in two categories, lung cancer and mesothc'.iomn. There were 19 deaths from lung cancer and 23 from mesothelioma among the former shipyard workers. As for the con trols, four died of lung cancer and none died of mesothelioma. Findings of an extraordinary increase of mesothelioma were also reported last year from the French shipyard area in Western Biiltany. Lnjnrtrc et ai. analyzed cases of pleural mesothelioma in Nantes. In the period- 1957-63, there were two cases; from 1S64-1970 there were 12; and from 1971-1974 there were 24.12 This was interpreted as consistent with the mark edly increased shipbuilding program dur ing and after World War II, and with its attendant risk of asbestos exposure. 90 CAA CANCER JOURNAL FOR CLINICIANS  -t.-- TABLE 4 Deaths among 17.E00 asbestos insulation workers in the United States and Canada, Jan. 1,1 967-Jan 1,1977: Analysis by duration from onset of employment Duration Num- from ber onset cf (years) men Personyears of observation Lun3 cancer Expected* Observed Pleural mesothelioma No./IOOO person-years Peritoneal mesothelioma No./lOOC person-years <10 10-14 15-19 20-34 25-29 30-34 35-29 40-44 45+ 5.552 5,0=3 9.S4 C.E57 6,59-3 3.547 2.C-19 1,103 1.030 25.393 29.003 34,069 3\2*3S 20.C57 1.598 5401 3.ICO 5.205 0.69 2.77 8.57 17.03 21.04 18.48 11.47 8.12 17.82 0 7 29 50 104 112 66 39 69 0 0 0.05 0.19 C.72 0.80 2.90 1.27 2.45 0 0 0.09 0.1C 0.87 . 1.90 3.33 5.00 5.47 Expected dcatr s ?re oascc upon white male ago specific mortality cata of the U.S. hJ&tiona I Cente' io? Health Statistics lor 1967-1976 and extrapolation to 1976: Smoking he*- *s :c*.en into account. ASBESTOS DISEASE IN U.S. SHIPYARDS There has been comparatively little writ ten concerning the potential for asbestosdisease hazards in U.S. shipyards. In part, this may have been due to the fact that in the latter part of World War 11 a survey directed to this question failed to demon strate the prevalence of significant asbes tos disease. At that time, 1,074 insulation workers employed in U.S. yards were examined and, with few exceptions, no evidence of disease was found.15 Unfortu nately, the significance of the fact that the very large majority of men had begun working only a short time before \V3S not appreciated; neither was it understood that X-ray evidence of disease could not be expected to appear until one or two de cades later. During the 1960's, evidence accumu lated that "asbestos workers" (insulation) employed in shipyards had unhappy dis ease experience, with markedly increased death rales of cancer (lung cancer, pleural mesothelioma, peritoneal mesothelioma, gastrointestinal cancer) and asbestosis.14 These observations, however, were con fined to insulation workers, and while they pointed to a possible accompanying difficulty among other shipyard trades, .expecially in view of British experience, detailed observations concerning other workers were not available. The potential for asbestos disease in U.S. shipyaids was further highlighted by accumulating knowledge that the workers who manufr ctured the asbestos insulation materials used in U.S. yards during and after World \Var II were themselves found to suffer scr ous asbestos disease. Investi gations of t! e employees at one such plant showed maikcdly increased risk of neo plastic diserse and asbestosis, including increased ri/k of death of cancer with as little as one month of employment.,5-14 VOL 28. NO 2 MARCH/APRIL 1978 91 HWBUI0002784 Fig. 1 S.P. &J.M. Extensive bilateral pleural calcification in former shipyard workers. -Asympto matic. No part ot pleura is immuneccsiei. diaporcgmatic, mediastinal, pericardial. Bilateral calcifi cation of this sort rarely seen except with prior asbestos exposur 5. Even wives and children of the employed workers showed evidence of asbestos dis ease, indicating that exposure of lesser intensity might be seriously hazardous as well.'7 ' RECENT SURVEY OF SHIPYARD WORKERS, GROTON, CONNECTICUT Cases of asbestos-associated disease among wotkers employed in a shipyard in Groton, in 1974-1975, were brought to our attention. Against the background of what was already known concerning the poten tial for asbestos disease in shipyards, it appeared useful to obtain information concerning whether there was the likeli hood of a high incidence of such disease or whether the cases seen were isolated, random exceptions. Lung cancer, mesothelioma, extensive asbesiosis and other serious complications of asbestos exposure arc late findings. Limited X-ray change (parenchymal, with in the lung, or pleura!) often precede these serious com equcnces. While such changes may occur to an extent visible by X-ray without subsequent cancer or disabling asbestosis, their. appearance among a group of workers provides evidence of prior significant asbestos exposure. Ab sence of such X-ray changes is no guar antee that important asbestos exposure has not occurred. Many workers may have had asbestos exposure sufficient to cause death from mesothelioma, for example, without showing X-ray change. Neverthe less, taken as a whole, absence of X-ray change in a group of workers suspected of having been exposed to asbestos provides some evidence that the exposure was lim ited. On the other hand, the presence of characteristic asbestotie X-ray abnormal ities is prima facie evidence that, overall, .there was important asbestos exposure in the group. In light of this, we sought to ascertain whether there was significant prevalence of asbestotk X-ray abnormalities among Groton shipyard workers. Examinations 52 CA-A CANCER JOURNAL FOR CLINICIANS Fig. 2 J.B. Both fibrotic piques and pleural calcilicalion in x-ray ot lorme' shipyard worker. Asymptomatic. Their presence is merely evi dence of prior asbestos exoosure and not in dicative that mesothelioma wiil necessarily follow. Fig. 3 J.YV. Age A 9. 1975. Truck driver until 1960. when he became "pipe ceverer" in a ship yard X-ray. fifteen years later, shows reticular (irregular) opacities o! moderate prolusion (2/2 in the ILO U/C Classification). Some shortness of breath on exertion. Note: infiltrate in lower lung tields. upper lobes clear. This is common. were largely limited to those whose em ployment had begun i5 or more years be fore; all were volunteers. A caveat is in order: there is no way of knowing, under these circumstances, whether those who volunteered were necessarily represen tative of the entire work force, or even of their specific employment category. Al together, 1,000 men were examined, in cluding 157 boilermakers, 121 pipefitters, 73 insulators, 82 painters, 69 carpenters, 117 welders, 10-1 electricians, 103 outside machinists, as well as laborers, moldcrs, lead bonders, office workers, draftsmen, guards, and decontamination technicians. Films were categorized using the Inter national Classification of Radiographs of Pneumoconioses (1 LOU/C) (Appendix 1). Overall, approximately half of the workers examined showed X-ray evidence of pulmonary and pleural changes of the sort regularly seen following direct or in direct occupational exposure to asbestos (pulmonary asbesto^is, pleural nsbestosis). The findings arc outlined in Tables 9 and 10. One or another abnormality was present in 274 of 636 workers with less than 20 years from onset of exposure (43.1 percent) and among 1.85 of 364 shipyard workers 20 or more years from onset (50.8 percent). Parenchymal disease was seen in 29.6 pcrcciit of the former group and 36.8 percent of the latter. Pleural changes were found in 23.1 percent of the less experi enced workers and in 29.7 percent of the men with longer experience. The high prevalence of pleural changes was not un expected, having been found previously among shipyard workers in Britain and elsewhere.:S The importance of duration from on set of exposure is clearly seen in Table 10, where it is found that among 303 workers who began work only in 1961 or later, 115 (3S.0 percent) had abnormalities on X-ray. In contrast, among 166' workers whose employment began in 1953 or before, 83 (51.2 percent) were abnormal. Nb trade was immune to changes. Tables 1! and 12 indicate that this W3s as true for painters as it was for electricians, for carpenters as for machinists, and for VOL 28. NO. 2 MARCH:APRIL 197G 93 TABLE 5 Deaths among 17,800 asbestos insulation workers in the United Stales and Canada, Jan. 1, ISGV-Jan. 1. 1877: Analysis by duration from onset of employment % Years from onset . of employment t Total deaths Lung cancer Percent of all deaths Mesothelioma Pleural Peritoneal - ^1C 10-14 15-20 20-24 25-29 30-34 35-39 <0-44 4b* 51 0 25 C.24 18S 15.43 220 18.44 388 26.80 340 32.94 253 20.09 203 19.21 442 15.61 c l> c 1.06 it: 1 .GO C.r4 3.86 4.64 2.94 6 47 6.32 7.11 1.97 7.ES 2.94 C 65 Tota1 G 0 2.0'J 8 40 9.41 12.42 9.85 . S.60 Total 2270 21.37 2.90 4.80 7.70 boilermakers as for welders. Review of work practices makes this quite under standable, of course. The conditions of shipyard work have been such that it is likely that asbestos exposure would have occurred among all individuals at a work site where the material was being installed, repaired or removed. Data are less certain for the less common crafts, where fewer workers were examined. Although evi dence of asbcstotic changes was found among some of these men and women as well, one can estimate a proportion only with less assurance. Thus, exposure to asbestos under past conditions, of an intensity sufficient to cause significant asbcstotic X-ray change, was common at the shipyard in Groton. As a result, a large number of workers' now have pulmonary changes associated with such exposure. The prevalence of such a high proportion of asbcstotic X-ray changes raises the question of increased risk of asbestos-associated neoplasms in the future. Those to be considered include cancer of the lung, pleural mesothelioma, peritoneal mesothelioma, and esophageal, stomach, colorectal, oropharyngeal, la ryngeal and renal cancer. The extent of this risk is not now known. CUT.RENT SITUATION In terms of public health, the overwhelm ing problem is the undoing, ameliorating or modifying of both current and antici pated results of past mistakes. The prob lems arc straightforward and, simulta neously, complex. To a considerable de gree, the complexity derives from the fact that we have had little experiencelo guide us in such matters, especially on the scale found in the present situation. The following recommendations-- 94 CA-A C-NCCH JOURNAL FOR CLINICIANS HWBUI0002787 necessarily incompleic and tentative -- arc offered: 1. Knowledge concerning asbestos expo sure: B Dissemination of information: under standing the disease potential of asbes tos exposure (past and future) would be valuable for both worker and manage ment. b Avoidance of additional exposure: appropriate engineering and industrial hygiene methods are' crucial; removal or repair of asbestos materials now in place presents a problem for the future. 2. Medical surveillance programs: b Asbestosis: awareness of the presence of this disease by both the patient and the treating physician would be im portant, since most deaths of asbestosis are due to inicrcurrcnt respiratory in fcctions, rather than to progressive pul monary fibrosis. Pulmonary infections can be well treated, and experience has shown that many lives can be saved. b Lung cancer: early diagnosis can in crease the likelihood of successful treat ment to some extent (by no means as much as we would like). It is not known whether more energetic surveillance (as with frequent sputum cytology examin ation) will increase the percentage of those successfully treated. Studies are now in progress to investigate this pos sibility. d Colorectal cancer: early diagnosis in creases the likelihood of cure. B Oropharyngeal, laryngeal or renal car cinoma: awareness of the increased risk of these cancers improves chances for early study and diagnosis of the pres ence of these conditions, which can be cured in many cases. b Pleural and/or peritonea! mesothelio ma: effective therapy is not now avail able and early diagnosis does not sig nificantly increase the likelihood of survival. However, research concerning therapy is now underway in the United States, Great Britain and France, and it .may be hoped that improved treatment methods will become available. n Education programs: Smoking: lung cancer risk is greatly TABLE 6 Percentage distribution of trades in private shipyards. June 1943 Trade Percentage Welders Snlpfitters > Machinists Pipefitters Electricians Carpenters Lat.orers Burners Painters Snectmetai workp-s Cmppers and csuiKers Ecne-TiaKers Crane operators 15.3 11.0 8.1 7.2 6.6 6.1 5.5 3.8 3.1 3.0 2.8 2.E 2.3 1.3 Fipe coverers 0.2 All other 21..1 Source: Bureau of Labor Statistics, Bulletin E24 multiplied by asbesios exposure.19 It is urgent that this information become available to workers who have been ex posed to asbestos, arid thal every assis tance be afforded them to help in their efforts to control and eliminate smok ing, especially cigarette smoking. Some data are also available suggesting that cessation of smoking will, after a num ber of years, reduce the risk of lung cancer, even with a history of prior cig arette smoking. Should these experi ences be confirmed, it will be even more urgent to identify and alert former ship yard workers,' to acquaint them with the important risk of lur.g cancer should they continue cigarette smoking. Cigar: ette smoking also increases the risk of serious disability associated with pul monary fibrosis, and of the dcvciop- VOl 28.NO 2 MARCH APRIL 1978 95 TABLE 7 Mesothelioma tumors in Devonport Dockyard. England. 19G4-1973* Asbestosis^ (disability) No. M 16 1C. a 36 23.1 15 S.6 4 2.6 15 5 5 ii 6 3.8 5 3.2 48 30.8 156 Occupation Sprayers Laggcrs Shipwrights Boilermakers Engine fitters Electricians Cauikers-Riveters Weioers All others Mesothelioma (deaths! No. ' 1 14 ' . 5 3 -s 11 55 *: 1 .z 'l .o 25.5 16.4 14.5 9.< 5.5 rr 20.G Harries. P.G. nv.r. Res. 11:261 -20/, 1976. TABLE 9 X-ray abnormalities among workers employed in shipbuilding and ship repair % TYPE OF ABNORMALITY Loss than 20 years from onset of shipyard em ployment (536) 20 or more years from onset of shipyard em ployment (364) Total Number % Number % Number Vo Any abnormality An parenchyma Parenchyma cr . ^ Paiencnyma & p aura Al: pitura Pieura only 274 168 127 61 147 86 43.1 165 50.8 29.6 1.34 35.8 20.0 77 21.1 S.G 57 15.7 '23.1 ' ' 103 ' 29.7 ' 13.5 51 14.0 459 204 118 137 45.9 32.2 i 20.4 11.8 25.5' 13.7 96 CA-A CANCER JOURNAL tor cumcia:;S HWBUI0002789 TABLE 8 Mortality experience of 429 shipyard workers :n Barron, England with pleural plaques on x-ray U9G4-1971) compared with control men in Carlisle, without pleural plaques Tracing to December 31. 1976 % Ai ive Dead Not traced Causes of death . Lung Cdric&r Mesotnelioma G. 1. cancer All other cancer Ischemic heart disease Chronic bronchit:s At; other causes Plaques 299 127 (305c! 3 (0.7%) <29 Plaques 19 23 . 7 13 34 9 22 Controls 34'7 ' 74 (17.2%) 6 l 1.9%) <29 Controls 4 0 < 7 29 c 21 TABLE 1.0 X-Ray abnormalities among workers employed in shipbuilding and ship repair, analysis by duration from onset of work Onset of work < 1950 1951-1959 195G-1S5C '-1901 Total 166 19C 303 1000 NORMAL No. % 81 9 17< 188 641 48.8 49.5 52.2 62.0 54.1 ABNORMAL No. % 85 io: 165 115 459 51.2 50.5 47.E 38.0 45.9 VOL ?8. MO 2 MARCH, APRIL 1976 97 HWBUI0002790 TABLE 11 X-Ray abnormalities among shipyard workers employed in shipbuilding and ship repair: major crafts . nATFfiORY ' All cratts painters Machinists (outside! Pipet iiters Insulators Electricians Boilermakers Welders Carpenters > T oral Year* from onset of shipyard work Atl groups 20 or more years Abnormal Abnormal Number Number % Number % 1000 459 45.9 185 =0.8 82 44 53.7 10/25 40.0 108 58 53.7 12/32 27.5 121 65 54.5 25/24 73.6 73 38 52.0 2/7 2E.6 104 55 52.9 23/34 67.8 157 80 51.0 41/84 48.8 117 42 35.9 25/48 52.1 09 3E 55.1 12/33 26.4 831 1000 459 45.9 ' 185/364 50.8 mcnl of cancer of the esophagus. Again, educational programs would be of value. informati> n is required for proper clin ical survei lance. 3.Assessment of the potential for ship yard asbestos disease: e Household contact asbestos disease: while families of asbestos workers are at risk, it is not known whether ship yard workers tended to contaminate their homes with appreciable amounts of asbestos in the pas:, and whether (his has resulted in d:\ea.ve risk. Such b \ecessary additional data: appropriate studies of mortality experience, status of retired workers and effects of mini- .mal expos :re are required for complete evaluation of the potential for future shipyard a ^bestos disease. Nevertheless, enough, is tow known to warrant rapid dcvclopnu nt of effective medical sur- seillhtice programs, further research can pi ocecJ apace. 98 CA A CI NCERJOURNAL TOR Cl It-JOANS TABLE 12 X-Ray abnormalities among workers employed in shipbuilding and ship repair: less common crafts Heavy equipment operators Laborers Inside machinists Molders Lead bonders Decontamination techn:cians Guards v./o previous joo. in yard Office workers -- Draftsmen w/o previous jcb ir. sard No. 13 7 30 12 21 12 12 37 Abnorr-.a S.'IC 17 lb'3C 4/5 2 7 ,'2 ' 5.12 3/12 16/37 r. 62 14 DC! 33 33 42 25 43 References 1. Bientz, M.; DiMcnza, L.; Nebul, M., and Bignon, J.: Rcgistrc dcs mcsotheliomcs malins dc la plcnrc cl du peritoine. Premiere rcsultats. Noyvelle Presse Med. 6:3114,1977. 2. Greenberg. M., and Davies, T.A.L.: Meso thelioma Register 1967-68. Brit. J. Indust. Med. 31:91-104, 1974. 3. Ziclhuis, R.I..; Vers'.eeb. J.P.J., and Plantcjdt, H.T.: neural mesothelioma and exposure to asbestos. Ini. Arch. Occup. Hnvir. Health 36:1-18,1975. 4. Selikoff, I.J.; Chtirg, J., and Hammond, E.C.: The occurrence of asbestoris among in sulation workers in the United States. Ann. N.Y. Acad. Sci. 132:13.9-155.1965. 5. Harries, P.G.: Asbestosis hazards in naval dockyards. Ann. Occup. Hyg. 11:135-145,1968. 6. Stumphius, J.: Epidemiology of mesothe lioma on Walcl'.crcn Island. Brit. J. Indust. Med. 28:59-66,1971. 7. McEwcn, j.; Fi.tlayson, A.; Mair, A., and Gibson, A.M.M.: Asbestos and mesothelioma in Scotland. I in. Arch. Arbeitsmcd. 28:301-311, 1971. 8. Fletcher, D.E.: A mortality study of ship yard workers with pleural plaques. Brit. J. Indust. Med. 29:142-145, 1972. 9. Harries, P.G.: Experience with asbestos disease and its control in Great Britain's Naval dockyards. Envir. Res. 11:261-267, 1976. 10. Edge, J.R.: Asbestos-related disease in Barrow-m-Furness. Envir. Res. 11:244-247, 1976. 11. Edge, J.R.: Personal communication, December 16,1977. 12. Laiartrc, M., ct ah: Mcsotheliomcs plcuraux diiYus c-t amiame. Ouest M-a. 29:615-621, 1976. 13. Fletcher, W.E.; Viles, F.J., Jr.; Cade, R.L., and Drinker, P.: A health survey of pipe covering operations in constructing naval ves sels. J. Tr.d. Hyg. Toxicol. 28:9-16, 1946. 14. Selikoff, I.J.: Disease prevention in as bestos insulation work. 1 nt. Symp. on Safety and Health in Shipbuilding and Ship Repainng, Helsinki, Finland, 1971. Occupational Safety and Health Scries 1/27,1LO, Geneva, 1972. 15. Selikoff, I.JHammond, E.C., and Churg, J.: Carcinopcnicitwof amositeasbestos. Arch. Env. Health 25:183-186,<972. 16. Seidtuan, K.; Lilis, R., and Selikoff, I.J.: Short-term asbestos exposure and cancer risk. Proc. Third Inti. Symp. Detect. Prev. Cancer, .1977. 17. Anderson, H.A., ct ah: Household-contact asbestos ncopt. ;tic risk. Ann. N.Y. Acad. Sci. 271:311-323, 1976. IS. Sheers, G., and Templeton, A.R.: Effects of asbestos in dockyard workers. Bril. Med. J. 3:574-579,1968. 19. Selikoff, -I.J.; Hammond, E.C., and Churg, J.: Asbestos exposure, smoking and neoplasm. JAMA 204:106-112,1968. VOL 28 NO ? MARCH APR:l 1978 99 HWBUI0002792