Document KJYZJ9ew76gpOYG49xyv9m9e6

MAY-06-04 QZiZOPM FROM- T-305 P.002/009 F-351 I ih, i| in. t ui tj Routes of asbestos exposure and the development of mesothelioma in an English region c n Denise Howe), Lorna Arb]aster, Layinka Swinburne, Martin Schweiger, Edward Renvoize, D: Paul Hatton y? d er h ic 4 n Iic , k) */r n F jr i. p n Nl n f y s ./ rI J: l i I l i i Department of Epidemiology und Public Health, llnivcnity of Newcastle upon Tyne D Howel Formerly; Department of Public Health, ' University or Leeds L Afblastcr St Jatpes's University Hospital, Leeds . L Swinburne Leeds Health Authority, Blenheim House, Leeds M Schweiger P Hatton United Leeds Teaching Hospitals, Leeds E Renvoize Correspondence nr. Denise Hftwel, Department ofEpidcrmoloey and Public Health, The Medical School, Frimlinittop Place, Newcastle upon Tyne NE4HH. Accepted 18 December 1998 Abstract Objectives--To investigate the contribu tion of exposure to asbestos through different routes in the development of mesothelioma. Methods--Case-control study, 185' con firmed cases of mesothelioma and 160 controls were identified, when death had occurred between 1979 and 1991 in four health districts in Yorkshire. The surviv ing relatives were interviewed to ascertain lifetime exposure to asbestos. Adjusted odds ratios (ORs) of exposure to asbestos (through occupational, paraoccupational, and residential routes) were calculated for Cases and were compared with controls. Results--Likely or possible occupational exposure to asbestos was more common in Cases than in controls (OR 5.6, -95%.confi dence interval (95% Cl) 3.1 to 16.1). After excluding those with likely or possible occupational exposure, likely or possible paraoccupational exposure was more common in cases than controls (OR 5.8, 95% Cl 1.8 to 19.2). Only six cases ofmes othelioma were identified as being solely exposed to asbestos through their resi dence, compared with nine controls. The OR for residential exposure to asbestos varied between 1.5 and 6.6, depending on which potential industrial sources were included, but the 95% CIs were so wide that slightly reduced or greatly increased odds comparing cases with controls could not be excluded. Conclusion--Study results support previ ous evidence that occupational and paraoccupational exposure to asbestos is associated with developing mesothelioma. Despite a rigorous search, purely residen tial exposure seemed to account for only 3% of identified cases. No firm conclusion can be drawn about the risks from residential exposure alone, as many of the study subjects could also have been occu pationally or paraoccupationally exposed to asbestos. (Owwp Ewirvrt M6 1997;54;403-409) Keywords: malignftnt mesothelioma; asbestos j nopoctupaiionil exposure Malignant mesothelioma is an uncommon cancer, often associated with exposure to asbestos, with a Latent interval between first exposure and rumour development averaging 30-40 years.'The death rate is expected to rise in Britain over the next 15--25 years,1 Although the risks of developing the disease from occupational exposure to asbestos are well established, those due to non-occupatiOnal exposure are of increasing concern. This study investigated the contribution of the different routes of exposure to asbestos (table 1) in the development Of mesothelioma; concentrating on occupational, paraoccupational, and rcsidential exposure. Over recent years, there has been public concern about the relatively high incidence of mesothelioma locally': occupa tional risks in three factories which used asbes tos in Leeds, Caldcrdaje, and York have been highlighted by the media. This study arose from further publicity about cases labelled as environmental by Her Majesty's Coroner or the local media and which were said to be linked to the Leeds factory. This factory closed in 1958, but considerable concern remains about continuing residential exposure to asbes tos in the vicinity of the factory.1 There has been recent legal action by some former local residents who have developed mesothelioma without occupational exposure io asbestos. However, many local factories used asbestos, and this study considers exposure to asbestos from all potential sources in the study area. . Subjects and methods study subjects Potential cases of mesothelioma were sought from the Health and Safety Executive's Na tional Mesothelioma Register, the Yorkshire Regional Cancer Registry, and local postmor tem records, where a previous diagnosis of mesothelioma had been made by a local pathologist, Subjects who had died from mesothelioma between January 1979 and December 1991 were considered for inclusion, if the address at death was in the Yorkshire dis tricts of Leeds, Calderdale, York, Wakefield, or Pontefract: these are largely urban areas in the north of England. Two pathologists then inde pendently examined available histological sec tions from each potential case. Results were classified into definite or possible malignant mesothelioma, or other tumour: only cases agreed to be definite mesothelioma were stud ied further. . Necropsy records were used io identify con trols for the cases. Sets of cases and controls were matched for sex, age at death (to within 10 years), and year of death (to within two years): the sets ranged in size from one case matched with one control, to six cases matched MAY-06-04 02:21PM FROM- Rouk Ocuipaiioiul Pinoceupuityiii) {domestic} Incidnrai exposure Rutidcnlijl exposure Gcnml cnviionntnial capMurt . Uatripdo w e] $op&i T-305 P.003/008 TnVes plfl [work ' Other people working with osbenoe who ihcd it from their elodiei or ptrjoo TtiroURh hobtirs or visits Living near a pirdcuku source of aib tttot 0seine or J'accory) In the environment without , pSrtieuJjr source F-351 with five controls. The choice of matched sets determined die occupational codes of the sub rather than matched pairs was considered to jects in the study. Also, the occupations of make best use of scarce subjects, when some members of the subject's household were simi will be dropped from later analyses. Potential larly coded, and the subject was assigned an controls were excluded if they, had died from overall code which reflected the highest level of mesothelioma, or diseases which couJd have paraoccupational exposure. Any incidental . been confused with mesothelioma (bronchial exposure to asbestos--for example, home or ovarian cancer), or iu circumstances in improvements--was coded likewise. which gathering information would be difficult Factories active from 1900 onwards in north (suicide; or if they had been homeless at the and west Yorkshire considered to use asbestos time ofdcath;oriftheyhad spent most of their and which might have emitted asbestos into the adult life in an institution). This did not give environment--for example, through loading, rise to many exclusions. Specimens of non- ventilation, or waste disposal--were identified tumorous lung tissue were obtained when through trade directories and local knowledge. available for Cases and controls, and were sent Altogether 278 were identified: many were only for mineral fibre analysis. These results will be active for short periods, and most were within discussed elsewhere. the Leeds or Bradford area. Only 83 of these Experience suggested that about 300 cases of factories ever had study cases or controls living mesothelioma would be identified in the Study within 0.5 Km of them. The factories wire clas period and area; however, we could only obtain sified as either group I (those where goods both histological material to confirm the diag containing asbestos were known to be nosis and a later exposure history On half of manufactured--for example, engine packing, these. Assuming one third of these cases had brake and clutch linings, joints and gaskets, not been exposed to asbestos through occupa railway carriages, or insulation materials) or tional or paraoccupational routes, there was an group 2 (those where this was in some doubt-- 80% power to detect an odds ratio (OR) =3 that is, the site may have been a warehouse, or linking residential exposure and mesothelioma asbestos may not have been the material used). at a significance level of 5%. Appendix 2 shows the activities at these facto ries. EXPOSURE HISTORIES A residential history, including schools < Attempts were made to contact the next of kin attended, was obtained at interview. The ofsubjects, and a semistructured questionnaire addresses of subjects within Yorkshire and was used to interview them to obtain a detailed potential industrial sources were converted, life history of the deceased. It was explained where possible, into the grid references ap that we were seeking information about the proximating to current postcodes. Distances deceased's life history, and they were encour were calculated between every residential aged to ask other family members or friends for address and every potential source, and then further details. Interviewees were unaware of the residential exposure of a subject was coded rhe main concerns of the study: only the final as; likely if residence was within 0.5 km of one few questions mentioned exposure to asbestos or more sources at some time; and unlikely if it explicitly. When it was not possible to interview - was not known whether residence was within relatives, information was sought from coro 0.5 km of any of these sources during life. ner's records. Permission for the study was Residential exposure was coded firstly for all obtained from local ethics, committees. potential sources, and secondly for those where Coding of exposure histories was performed manufacture of asbestos goods was more blind to case-control status, and was based on certain (group 1 only). The figure shows the responses obtained before asking explicitly grid references both of addresses where about asbestos exposure. It was assumed that subjects lived and the factories which were asbestos exposure in the last 15 years of life (by potential sources of asbestos to the environ whatever route) would not have contributed to ment. rite development of mesothelioma, and this period was excluded when coding information. STATISTICAL analysis Occupational and paraoccupational exposures The main technique used for the analysis of the of less than one month were excluded, as were Comparative risks of exposure was conditional residential exposures of less than one year. logistic regression." Occupational and paraoc Occupations were coded with an existing cupational exposure were coded to three levels classification1 as likely, possible, or unlikely to --likely, possible, and unlikely. The analyses have Jed to exposure to asbestos. Each Subject were carried out with two sets of groupings. was then assigned an overall code, which was Firstly, by comparing likely and possible with the highest level of occupational exposure ever the unlikely group, and secondly, by comparing experienced. Appendix 1 lists the jobs which likely with the possible and unlikely groups. 06-04 02:ZIPM FROM- r4fiDO O*700 Subjects' addresses -+- Industrial sources of asbestos 4800 4500 T-305 P.004/008 F-351 oo o o Jj 4400 d, 4300 o 4200 4100 - Huddersfield Q 4000 3900 4000 4100 4200 4300 4400 Grid reference east Position ofsubject mhlreisct unci pvftntial industrial sources oj ofto ros 4SD0 4600 4700 4300 The conditional logistic model incorporated terms to further adjust for the age, year of death, and district; as the matching criteria were quite wide. The cRecta of exposure to asbestos by a particular route was evaluated by successively excluding subjects who had been exposed to asbestos by routes which were likely to be sc higher levels--for example, excluding occupational exposure while considering paraoccupational exposure. The same matched sets were used for all analyses, but exclusions were made as already described: if all cases in a set were excluded for this reason, the controls in the set were not used. Results There were 316 potential cases of mesothe lioma identified: 71 of these could not be con . firmed, it was agreed that 15 were not mesothelioma, and fqur were possible meso thelioma, leaving 226 confirmed cases. The relatives of 133 of these cases were interviewed and information on a further 52 cases was obtained from the coroners' records. Interview information was obtained for all 159 controls. ToWc 2 Characteristics vj eases uni controls Age uldejth (median (laufifi)) Men (>(%)) . Died in : Lccd, . Catderdale Wakefield York Com (n~lSS) 66 (38-89) . 137 (74) 135 (73) 22(12) 19 (ID) 9(5) Controls (rt-159) 67 (38-85) 1)8(74) 122 (77) 20 ()3) 13W 4(3) These were divided into 55 sets of cases and controls. Tbble 2 shows die distribution of age, sex, and place of death for cases and controls. COMPARING EXPOSURE TO ASBESTOS IN OASES AND CONTROLS fOX EACH EXPOSURE ROUTE Overall, 103 (56%) of the cases were classified as likely to have been occupationally exposed to asbestos, compared with 22 (14%) of the con trols. Inclusion of those who had possibly been exposed, gives corresponding figures of ISO (81%) and 80 (50%). The source of infor mation about occupational history had little association with the exposure category, Among those whose work history came from interview 55% had likely occupational exposure, 26% possible, and 19% unlikely, with corresponding proportions in the cases in which the infor mation came from coroner's records of 58%, 25%, and 17%. In most matched sets the cases had the same or a greater chance of being occupationally exposed than the controls: there were 41 sets where there were a higher proportion of cases than controls who had been likely or possibly occupationally exposed, II sets where the proportions were equal, and three sets where there was a higher proportion of controls, Table 3 shows the condtional logis tic regression results, and show that the odds on having occupational exposure were consid erably higher in esses than controls. It was considered inappropriate to compare paraoccupational exposure of subjects who have also been occupationally exposed to asbestos. Two analyses hayc therefore been MAY-16-04 02:21PM FROM- T-305 P.OD5/OOB F-351 OR (9S% C!) OecuputioDil exposure; Litdy d pnuible ind unlikely Likely and possible i/ unlikiily PanoEcvpfcniial u^deuk; Excluding subject* with likely occupnionul expoiure: Likely v possible and unlikely Likely and pottible v unlikely Excluding (hole With likely or possible occupations! exposure: Likely v poniblc and unlikely Likely and pojlible u unlikely Rejidemia! exposure; ' Excluding tybjecit with likely occupational exposure or likely pireoCCupationol cxpoiure; Likely v unlikely (usini; group 1 sources) Likely si unlikely (using all source*) Excluding subfeen with likely or JJOIiible oempMiOM) exposure ind likely pussceupaticnil exposure; Likely o unlikely (using group I source*) Likely u unlikely (using all sources) Excluding subjects with likely or possible occupational expoiure and likely or possible paraoceupmional exposure; Likely u unlikely {using group 1 soureei) ' Likely v unlikely (usiug all jources) . 9.1 (4.8 to 17.1) 5.613.1 to 10.1) 5,6 1.910 16-5) 1.0 (O.S7 w 3.6) 61.7 (3.1 to 1104) 5.B (1.7 to 19.2) 1.7 ((1.70 to 3.8) 2,0 (0.9 to 4.2) 1.9 (0.51 10 7.1) 1.5 (0.46 to 5.1) 6.6 (0.86 to 50) 2.3 (0.54 9.7) done: excluding subjects with likely occupa It was considered inappropriate to compare tional exposure, and excluding those with likely the residential exposure of cases and controls if or possible occupational exposure. Altogether they had also been exposed to asbestos by other 45 matched set; remained, comprising 81 cases routes likely to have been at higher exposure and 124 controls, for the first analysis. Eighteen levels. Therefore three analyses were carried of these cases had likely and five had possible out; excluding subjects with likely occupational paraoccupational exposure; five of the available exposure or likely paraoccupational exposure; controls had likely and lb had possible paraoc excluding subjects with likely or possible occu cupational exposure. Table 3 shows ihe ad pational exposure and likely paraoccupational justed OR estimates. The odds of paraoccupa- exposure; and excluding subjects with likely or tional exposure were higher in cases than possible occupational exposure and likely or controls, whether the possibles were included possible paraoccupational exposure. Table 3 with the likely or unlikely exposure groups. Shows the adjusted OR estimates. However, when the possible group was com Thirty five matched sets comprising 46 cases bined with the likely group, the 95% confi and 96 controls were usable for the first analy dence interval (95% Cl) for the OR showed sis. Of the 46 cases, 25 had lived within 0.5 km that dara were also consistent with equal odds of any potential source, and 20 in group 1 had ofparaoccupational exposure. lived within 0.5 km of a potential source. The Only 27 matched sets, comprising 34 cases corresponding figures for the 117 controls were and 58 controls, were usable for the second 32 and 24. There were only 17 matched sets analysis. Of these cases 13 had likely and four comprising 18 cases and 40 controls who were had possible paraoccupational exposure) three ' usable for the second analysis. Of the 18 cases, of the controls had likely and eight had possible eight had lived within 0.5 km of any potential paraoccupational exposure. By excluding a source, and six in group 1 had lived within 0.5 further group of subjects who might have been km of a source. The corresponding figures for occupationally exposed, we should obtain a less the 69 controls were 13 and nine. There were biased estimate of the strength of the associ only 14 matched sets comprising 14 cases and ation but the estimate was much less precise, 29 controls who were usable for the third because of the reduced numbers of subjects analysis. Of the 14 cases, six had Jived within available. The point estimates of ORs sug 0.5 km of any potential source, and five in gested a much stronger association, but were group 1 had lived within 0.5 km of a potential consistent with ORs both, little greater than source. The corresponding figures for the 56 unity and very high indeed. So whereas the controls were nine and five. odds on paraoccupational exposure were The estimated OR on residential exposure to higher for cases of mesothelioma, we are asbestos comparing cases with controls rose as unable to say with any precision by how much each of the other sources of exposure was they were raised. excluded. However, the few subjects remaining Forty four cases and 43 control; reported without occupational and paraoccupational some activities which could be coded as possi exposure do not allow us to estimate the ble incidental exposure. These included car or strength of the relation between residential motorbike repair, removing fireplaces or waits exposure and mesothelioma with sufficient at home, installing central heating or lagging precision to rule out either no association or a pipes, dismantling radiators, demolishing a Strong association. coke oven, and unspecified home improvement tasks. There were three controls for whom this RELATIVE CONTRIBUTIONS OF THE DIFFERENT seemed to be the only asbestos exposure, and TYPES OF ASBESTOS EXPOSURE two cases and five more controls for whom only Altogether 45% of the exposure histories incidental and residential exposure were iden collected in this study reported asbestos expo tified, The vague exposure descriptions pre sure by more than one route. It is impossible to cluded formal analysis. be certain which was the dominant exposure I I Iu c ii p i* T 06-04 02:21PM FR0M- Tabic 4 Main mute ofexposurefor cases and controls (n(%)) T-305 P.006/D0B F-351 Category Occupational Pflriioccupational Incidental Rtijidtjuial None or unknown Total Dcjcriphonf Costs Liktlyor pfMlibly Dccupirioaally exposed tikdy or possibly ptracscuperionslly expoied ind not occupationilly cxpoicd {likely or poiliblc) Likely or {Witiblc incidentally exposed but not occupationally Or punaocrupatippnIfy exposed (lively or possible) Likely mideDDil exposure 10 any imircr but not occupatonalky> panoccupaponnlly, nr iiciden tally exposed (likely or pOHlbJt) ' Subject! not thought to be cXpOtfid to Asbestor, by any of the abovu routes (this will include subject! whoc cicpenure hficoryhac musing iciXormntion) 150(82) 17(9) 2(1) e<3) ' 10(5) 185 (100) Control* HD (SO) 14 ( 8(5) M (9) 43 (27) 159 (100) Total 230 (67) 31 (9) 10(3) 20 (6) 53 (15) 34.4 (J00) route for each subject; nevertheless, a hierarchy and 9.5% of controls had lived in the vicinity of of exposure categories has been suggested It is an asbestos friction materials plant.' These assumed ihat occupational exposure to asbes results are not comparable with each other, or tos has the highest level: lesser exposures are with this study, because of the varying deemed to be poraoccupational, incidental, definitions. Outdoor airborne asbestos concen and residential. Subjects have been grouped trations were found to be raised near a factory into five categories, and table 4 shows the number of cases and controls in each of these. Occupational exposure was the most common route in both cases and controls. Only 5% of cases seemed to have no exposure to asbestos, whereas the figure was 27% for the controls. that made asbestos slate board, and near an asbestos-cement plant,11 u but in general, little js known about the likely increase in airborne asbestos concentrations near factories that used asbestos, or about the area over which this increase might be expected. Given the established risks of occupational Discussion The hazards of occupational exposure to asbestos have been documented for decades. Wagner er of first established the link between working at, or in close association with, an asbestos mine and development of mesotheiioma, and subsequent papers have described the risks associated with other occupations. Of study cases 82% had likely or possible occupa tional exposure, compared with 50% of the controls. Comparisons with orher case-comxoi studies are complicated by differing occupa tional coding schemes, but there were similar proportions of occupational exposure in the cases and controls in a North American study (70% and 51% respectively),1<I and fewer so exposed in a London study (41% and 11%)." Our study confirmed that the odds of having a likely or possible occupational exposure to asbestos arc significantly higher in cases than controls. It is generally accepted that there is a link between paraoccupational exposure to asbestos and mesothelioma. Case-control studies in London," New York,1* and North America'0 and paraoccupational exposure, a major focus of our study was the hypothesis that living in the vicinity of a factory that used asbestos is a risk factor for mesothelioma. No Study has looked at residential exposure so comprehen sively. Many potential industrial sources of asbestos were identified in the study area, as well as the sources which provoked public and media concern. However, only a few sources were near the residences of study subjects, and very few after the exclusion of subjects with occupational and paraoccupational exposure. There were more subjects with occupational or paraoccupational exposure than expected from other studies: this may be because there was genuinely more exposure by these routes in Yorkshire in the study period, or because we obtained more complete exposure histories, or differences in definitions. We had assumed that one third of the cases would have been unexposed through occupational or paraoccu pational routes, but the actual figure was 9.7%, leaving relatively few cases available for that part of the study that concentrated on residen tial exposure. No firm conclusion can therefore found a history of paraoccupational exposure be drawn from this study about the risks of to asbestos in more eases than controls, residential exposure, because of the small although the numbers were small. This study number of suitable subjects. The estimated OR supports previous evidence about paraoccupa- for residential exposure to asbestos varied tional exposure, but the size and precision of between 1,5 and 6,6, depending on which sub the OR depends on whether we include those jects and sources were included, but the 95% possibly exposed with those likely or unlikely to CIs were so wide that slightly reduced or be paraoccupationally exposed. greatly increased odds comparing cases with The risk of residential exposure is less clear. controls could not be excluded. Some case-control studies have investigated The 0,5 km radius from a potential indus the role of residential exposure after excluding trial source ofasbestos is arbitrary; it is a proxy other asbestos exposures. The London study for exposure from a particular source. It is not found 11 cases compared with five controls liv assumed that airborne asbestos from the ing within 0.5 miles of a particular asbestos potential source is necessarily found at any factory." The New York study found one case residence within 0.5 km. Living dose to a living 1.2 km from an asbestos factory, and no source may mean chat the subject often walked controls nearby.52 The North American study past it, or played in the factory yard, etc. Also, found that one case and four controls had lived tlte identified sources carried out a wide range within 20 miles of ehrysotile mines.*" A of industrial activities with asbestos; some were Connecticut smdy found that 9.2% of cases known to process large amounts of raw fibre, HAY-D6-04 02:22PM FROM- ,, T--305 P.007/000 F-351 UUtWia umj UIUJ JWlvi** goods. The use of trade directories and local detailed histories of asbestos exposures, and knowledge to identify premises used by the ' has provided valuable information on Che risks asbestos industry may be insufficiently precise. of occupational and paraoccupational expo If residents in the vicinity of some ofthe poten sure, and made a useful contribution to the tial sources were not exposed to asbestos, or study of residential exposure to asbestos. A only at distances <0.5 kra, their inclusion will ' high proportion of both cases and controls underestimate the risk from larger industrial could have been exposed to asbestos at work. sources of asbesios. However, more detailed Although heavy exposure through the manu information about the manufacturing proc esses at the various factories is rarely available, preventing more precise estimates of their potential for releasing asbestos into the envi ronment Nor was it possible to determine which type of asbestos was used in many facto ries, although the Leeds factory, which had provoked concern, was known to use mainly crocidolite, and the Cdlderdale factory used crocidolite and brown asbestos (amosite) for long periods." " This and other case-control studies suffer from the fact that retrospective asbestos expo sure histories are likely to be incomplete: relalives providing information may not be aware of, or be able to recollect, important occupalions or residences, particularly if these were of short duration. The quality of information var ied: some informants were able to provide very detailed life histories, others were vague about particular periods ot aspects of the subject's life. There ate also difficulties in trying to ascer facture of asbestos products has fallen over the years, there is still scope for exposure in work ers engaged in repair, renovation, and demolilion of buildings containing asbestos, the $0 called "third wave of asbestos disease".17 Prevention requires rigorous enforcement of existing legislation, workforce education, and surveillance to ensure .chat existing standards are adequate to identify other potential causes of mesothelioma. Only 3% of the cases were associated solely with residential exposure, and it is not possible to conclude from this study alone whether such exposure is a risk factor for development of mesothelioma. A larger study is needed to do this. It is important chat all possi ble sources of asbestos exposure should be considered and thoroughly investigated in cases of mesothelioma. For instance, 25 of the cases of mesothelioma in Leeds between 1971 and 1987 were labelled as due to environmen tal exposure to asbestos by Her Majesty's Coroner or the local media, but further investi tain the key routes of asbestos exposure when a gation established that 20 of these could have life history suggests exposure from more than been occupationally or paraoccupationaliy one route. For example, whereas a weaver of exposed.1" At present, such investigations are asbestos products would almost certainly have performed on an ad hoc basis, but it would be been exposed to very high levels of asbestos useful to determine whose' responsibility this which would dominate those from other should be. Combining the results of such routes, an electrician (coded as possible inquiries would provide a means of obtaining a occupational exposure) might have limited Sufficiently large database from which the role asbestos exposure at work, but higher exposure as the result of living near aii asbestos factory, or from a family member working there. We have assumed that occupational exposure of residential exposure in the development of mesothelioma jn the community could be reconsidered. dominates that from other sources in this study The few studies which have measured airborne asbestos concentrations in non-occupational settings indicate that paraoccupational expo sure can lead to higher concentrations than residential exposure'*, .but we cannot be sure that this is the case for all the subjects in this study. We dye particularly grateful to the contort* preLc eatci of mea- aihctioma and those who acted ** consol^ for [heir help and interest; And to Dr Philip E da, Co*tu, contuliaat pathologist, Stacroft and Kflllnchcck Hospital, Tor cuxryine out htaologicai confirmation of the cases. Vt/c nfao acknowledge lupporr given by naff at local pathology laboratories and medical record* depoTtyncnb^ *taff at local office* of Her Coroner and stiff at the University of Leeds Medjcal Library, Leeds City Library, and Bradford City Library, The ttudy ww funded by the Coll Foundation. There arc no conflicts of interest. Appendix It lint of job& that determined the clu&eification of subjects into each occupation?! clans of exposure to asbestos, LIKELY . Asbestos factory worker (fitter, sprayer, carding, packer, mattress maker, maintenance, spinner, etc), boilermaker, bricklayer, builder's labourer, built gas retorts, built railway coaches, display work using asbestos, dockwork involving asbestos, fitter on ships, finer using asbestos, foreman using asbestos, gas fitter, heating engineer or plumber, joiner using asbestos, laboratory technician using asbestos, lagger, maintenance involving asbestos, metal worker using asbestos, munitions woik involving asbestos, naval engineer using asbestos, power station worker, roofer or slater, shipyard worker. POSSIBLE Aircraft mechanic, air raid warden, architect, boilerman or stoker, car mechanic, chemist, clerk at asbestos goods factory, cleaner in asbestos goods factory, driver of asbestos loads, electrician, engineer, fireman, fitter, foreman, foundry worker, Hoffman presser, industrial brush repair, MAY-0G-04 ;ether , and risks expoo t' 5S ltTOla vork. Lanur the forknoii- e so it of and ards uses vcre and udy r for lyis tssibe in the >71 enty's atiave illy are fc hi. ich ga ?le of be iCfi- ubd in, caJ fen rd* Ad :iiy by 02:22PM FROM- >305 P. 008/009 F-35! joiner, laundry worker (ironing), maintenance work, metal worker, munition worker, painter, railway worker, scaffolder, stonemason, rank gunner, telephone engineer, welder, UNUKELT Baker, barman, catering, cinema manager, dcancr, clerk, clothing industry worker (machinist, . tailor's cutter, finisher, etc), colliery worker, draughtsman, driver, dyeworker, Factory work, farm- work, film editor, groundsman, hairdresser, laundry worker, letter sorter, manager, navy, nurse, paver, postman, priest, sales assistant, shoemaker, teacher, tiler, upholsterer, warehouseman, wireworker. Appendix Z: Activities at potential industrial sources of asbestos near Yorkshire residences ofstudy subjects Group l--likely jitanLi/acrurc uting asbcMos: Aabeiuai goads mvmtiicturcrs Engine packing, noun pecking, or metallic packing nKmulaueureti Brake sod clutch manufacturer* Jointing and gasket manufacturers Railway carriage and locomotive manoficniren Insulation, boiler covering, or packing manufacturer! Pibroui platter or fibrous ctmem minufaccurci* Group 2--Twy be arurage only, or anbuioi not used: Asbestos building materials, asbestos cement* aibestoa roofing Insulation specialist^ engine packing, fireproofing, iteam products manufacturer Ibta} Number cf laurces within O.S km of 9 f iruety subject 17 13 7 J 7 1 9 1o IS S3 1 TjJcou JA, Amman KH. Asbestos related rrtaUpmtty Cmcttl problems w cancer, Cbicagtr yfar bcvJc, Chicago:. Medical Publishers, 1968. Z Dr Klerk NH, Armstrong BK. The epidemiology of aibei- tor and mesothelioma. In; Henderson D\6 i'hilkirt KB, Langtau SL, Whitaker D, cdt. AfaJtjpiPtc mewiAe/weta, New York: Hemisphere, 1992:223-50. 3 Palnar PV, Further evidence of nan-usbesteu related mesothelioma, A review of die literature. Stand J Ufa* Environ Health )96B;X4:14t-4. 4 Pew J, Hodgson JT, Matthews FE, Jones JR- Continuing increase in mesothelioma mortality in. Britain. Lancet 1995; 345;535~9. 5 Gardner MJ, Aeheson D> Winter PD. Mortality from mes- othdipipn of die pleura during 1968-7H in England and Wales. BrJCanar 1982;46;81-&. 6 Arbiter L, Hatton P, Remuta ER> Schweipcr MS. Leeds mesothelioma deaths 197f-67. Leeds: Leeds Western Health Authority, Leeds Eastern Health Authority, and Leed i City Council, January 1990. 7 Tea MJ, Uwiueba HC, Mtip J, Winer V, Romeo A, Mownd L2, ft aL Mesothelioma in Connecticut, 1955-77. /Octtip Med 193;25i74M6. H Colletr D. tAadeHinj* binary data. London: Chapman and Hall, 1991, 9 Wagnei \t Slegi C, Marchand P. Diffuse pleural mesothe lioma iiod abdtoi exposure in the North Western Cape Province. Br find Med 1960;17:260-71. 19 McDonald AD, McDonald JC. MflMenant mesoitKliomn In Nurch Amedeo. Cancer 1960;46:1650-6. J ] Newhou*e M, Thompson H. Meu theJionja of (he pleura and peritoneum following exposure to asbestos in the Lon don uno.BrJJnJMed 1965;22:261-9. 12 Vianna NJ, Pnbn AK,. Non*oecupatiobs1 exposure 10 psbe*- [ and malignant mesothelioma in females. Ljireet 197ft;i: 1061 *-3. J 3 Lebcl. Review offibre concentrations in Quebec asbestos Htinmg towns. Quebec: Quebec Asbestos Mining Association, 1964. 14 Kohyama N. Airborne asbestos levds in non-oceupational environments in Jnpun. In: Bignon J, ed, Nen-eKupwipHa! exposure to mineralfibres, Lytm: 1ARC, l909:Z6Z-76. 15 Edward AT, Whitaker D, Browne X, Pvolej FD, Cibbl AR. Mesothelioma in the north of England. Oceup Eaviwn Med 1996;;547-52* . 16 Nicholson wj, Retil AN, Welsmon ]r Sdikoff &, Environ- nveotfll aubextot coneentrtitipns. In: Wagner jC.ed. Bietpgi* cyf effects uf mwwruifibres. Lyon.' IARC, 19flU!&23'-7, 17 Landrigan P. The third wave of asbestos diiease; exposure to asbenos in pfoct [prefneel. Ann New York Atad S<i 1991;643:15-6. 10 Axbbitcr L, Hutton Howe} D, RcOvoixc , Schweigor M, Swinburne LM. Occupational and environmental links to mesothelioma deaths occuringin Leedi during 1971-87. J Public Hvutlh Med 1995)17:297-304. of *y n ts r> Lt