VIEWS: 16 PAGES: 7 POSTED ON: 11/25/2011
Occupational and Environmental Medicine 1997;54:403-409 403 Routes of asbestos exposure and the development of mesothelioma in an English region Denise Howel, Lorna Arblaster, Layinka Swinburne, Martin Schweiger, Edward Renvoize, Paul Hatton Abstract 30-40 years.' The death rate is expected to Objectives-To investigate the contribu- rise in Britain over the next 15-25 years.4 tion of exposure to asbestos through Although the risks of developing the disease different routes in the development of from occupational exposure to asbestos are mesothelioma. well established, those due to non-occupational Methods-Case-control study. 185 con- exposure are of increasing concern. This study firmed cases of mesothelioma and 160 investigated the contribution of the different controls were identified, when death had routes of exposure to asbestos (table 1) in the occurred between 1979 and 1991 in four development of mesothelioma; concentrating health districts in Yorkshire. The surviv- on occupational, paraoccupational, and resi- ing relatives were interviewed to ascertain dential exposure. Over recent years, there has lifetime exposure to asbestos. Adjusted been public concern about the relatively high odds ratios (ORs) of exposure to asbestos incidence of mesothelioma locally5: occupa- (through occupational, paraoccupational, tional risks in three factories which used asbes- and residential routes) were calculated for tos in Leeds, Calderdale, and York have been cases and were compared with controls. highlighted by the media. This study arose Results-Likely or possible occupational from further publicity about cases labelled as exposure to asbestos was more common in environmental by Her Majesty's Coroner or cases than in controls (OR 5.6, 95% confi- the local media and which were said to be dence interval (95% CI) 3.1 to 10.1). After linked to the Leeds factory. This factory closed excluding those with likely or possible in 1958, but considerable concern remains occupational exposure, likely or possible about continuing residential exposure to asbes- paraoccupational exposure was more tos in the vicinity of the factory.6 There has common in cases than controls (OR 5.8, been recent legal action by some former local 95% CI 1.8 to 19.2). Only six cases of mes- residents who have developed mesothelioma othelioma were identified as being solely without occupational exposure to asbestos. exposed to asbestos through their resi- However, many local factories used asbestos, dence, compared with nine controls. The and this study considers exposure to asbestos Department of OR for residential exposure to asbestos from all potential sources in the study area. Epidemiology and varied between 1.5 and 6.6, depending on Public Health, which potential industrial sources were University of included, but the 95% CIs were so wide Subjects and methods Newcastle upon Tyne that slightly reduced or greatly increased STUDY SUBJECTS D Howel Potential cases of mesothelioma were sought odds comparing cases with controls could not be excluded. from the Health and Safety Executive's Na- Formerly: Department tional Mesothelioma Register, the Yorkshire of Public Health, Conclusion-Study results support previ- University of Leeds ous evidence that occupational and Regional Cancer Registry, and local postmor- L Arblaster paraoccupational exposure to asbestos is tem records, where a previous diagnosis of associated with developing mesothelioma. mesothelioma had been made by a local St James's University pathologist. Subjects who had died from Hospital, Leeds Despite a rigorous search, purely residen- tial exposure seemed to account for only mesothelioma between January 1979 and L Swinburne December 1991 were considered for inclusion, 3% of identified cases. No firm conclusion Leeds Health can be drawn about the risks from if the address at death was in the Yorkshire dis- Authority, Blenheim residential exposure alone, as many of the tricts of Leeds, Calderdale, York, Wakefield, or House, Leeds study subjects could also have been occu- Pontefract: these are largely urban areas in the M Schweiger north of England. Two pathologists then inde- P Hatton pationally or paraoccupationally exposed to asbestos. pendently examined available histological sec- United Leeds Teaching tions from each potential case. Results were Hospitals, Leeds (Occup Environ Med 1997;54:403-409) classified into definite or possible malignant E Renvoize mesothelioma, or other tumour: only cases Keywords: malignant mesothelioma; asbestos; non- agreed to be definite mesothelioma were stud- Correspondence to: occupational exposure ied further. Denise Howel, Department of Epidemiology and Public Necropsy records were used to identify con- Health, The Medical School, trols for the cases. Sets of cases and controls Framlington Place, Malignant mesothelioma is an uncommon were matched for sex, age at death (to within Newcastle upon Tyne NE2 cancer, often associated with exposure to 10 years), and year of death (to within two 4HH. asbestos, with a latent interval between first years): the sets ranged in size from one case Accepted 18 December 1996 exposure and tumour development averaging matched with one control, to six cases matched 404 Howel, Arblaster, Swinburne, Schweiger, Renvoize, Haton Table 1 Routes of asbestos exposure Route Description of exposure Occupational Takes place at work Paraoccupational (domestic) Other people working with asbestos who shed it from their clothes or person Incidental exposure Through hobbies or visits Residential exposure Living near a particular source of asbestos (mine or factory) General environmental exposure In the environment without a particular source with five controls. The choice of matched sets determined the 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 could have paraoccupational exposure. Any incidental been confused with mesothelioma (bronchial exposure to asbestos-for example, home or ovarian cancer), or in 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 of death; or if they had 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 were clas- period and area; however, we could only obtain sified as either group 1 (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 of subjects, 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 the 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. the 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.8 Occupational and paraoc- Occupations were coded with an existing cupational exposure were coded to three levels classification' as likely, possible, or unlikely to -likely, possible, and unlikely. The analyses have led 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. Routes of asbestos exposure and the development of mesothelioma 405 4800 r 4700 H 0 Subjects' addresses 0 + Industrial sources of asbestos 4600 F- 90 York 0 4500 F- to 0 To C G) C.) C 4400 e 09 a) 0 4300 0 4200 4100 Huddersfield 0 4000 3900 4000 4100 4200 4300 4400 4500 4600 4700 4800 Grid reference east Position of subject addresses and potential industrial sources of asbestos The conditional logistic model incorporated These were divided into 55 sets of cases and terms to further adjust for the age, year of controls. Table 2 shows the distribution of age, death, and district; as the matching criteria sex, and place of death for cases and controls. were quite wide. The effects of exposure to asbestos by a particular route was evaluated by COMPARING EXPOSURE TO ASBESTOS IN CASES successively excluding subjects who had been AND CONTROLS FOR EACH EXPOSURE ROUTE exposed to asbestos by routes which were likely Overall, 103 (56%) of the cases were classified to be at higher levels-for example, excluding as likely to have been occupationally exposed to occupational exposure while considering asbestos, compared with 22 (14%) of the con- paraoccupational exposure. The same matched trols. Inclusion of those who had possibly been sets were used for all analyses, but exclusions exposed, gives corresponding figures of 150 were made as already described: if all cases in a (81%) and 80 (50%). The source of infor- set were excluded for this reason, the controls mation about occupational history had little in the set were not used. association with the exposure category. Among those whose work history came from interview Results 55% had likely occupational exposure, 26% There were 316 potential cases of mesothe- possible, and 19% unlikely, with corresponding lioma identified: 71 of these could not be con- proportions in the cases in which the infor- firmed, it was agreed that 15 were not mation came from coroner's records of 58%, mesothelioma, and four were possible meso- 25%, and 17%. In most matched sets the cases thelioma, leaving 226 confirmed cases. The had the same or a greater chance of being relatives of 133 of these cases were interviewed occupationally exposed than the controls: there and information on a further 52 cases was were 41 sets where there were a higher obtained from the coroners' records. Interview proportion of cases than controls who had been information was obtained for all 159 controls. likely or possibly occupationally exposed, 11 sets where the proportions were equal, and Table 2 Characteristics of cases and controls three sets where there was a higher proportion of controls. Table 3 shows the condtional logis- Cases (n=185) Controls (n=159) tic regression results, and show that the odds Age at death (median(range)) 66 (38-89) 67 (38-85) on having occupational exposure were consid- Men (n(%)) 137 (74) 118 (74) erably higher in cases than controls. Died in (n(%)): Leeds 135 (73) 122 (77) It was considered inappropriate to compare Calderdale 22 (12) 20 (13) paraoccupational exposure of subjects who Wakefield 19 (10) 13 (8) have also been occupationally exposed to York 9 (5) 4 (3) asbestos. Two analyses have therefore been 406 Howel, Arblaster, Swinburne, Schweiger, Renvoize, Haton Table 3 Adjusted ORs of asbestos exposure and mesothelioma OR (95% CI) Occupational exposure: Likely v possible and unlikely 9.1 (4.8 to 17.1) Likely and possible v unlikely 5.6 (3.1 to 10.1) Paraoccupational exposure: Excluding subjects with likely occupational exposure: Likely v possible and unlikely 5.6 (1.9 to 16.5) Likely and possible v unlikely 1.8 (0.87 to 3.6) Excluding those with likely or possible occupational exposure: Likely v possible and unlikely 61.7 (3.4 to 1104) Likely and possible v unlikely 5.8 (1.7 to 19.2) Residential exposure: Excluding subjects with likely occupational exposure or likely paraoccupational exposure: Likely v unlikely (using group 1 sources) 1.7 (0.78 to 3.8) Likely v unlikely (using all sources) 2.0 (0.9 to 4.2) Excluding subjects with likely or possible occupational exposure and likely paraoccupational exposure: Likely v unlikely (using group 1 sources) 1.9 (0.51 to 7.1) Likely v unlikely (using all sources) 1.5 (0.46 to 5.1) Excluding subjects with likely or possible occupational exposure and likely or possible paraoccupational exposure: Likely v unlikely (using group 1 sources) 6.6 (0.86 to 50) Likely v unlikely (using all sources) 2.3 (0.54 to 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 sets 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 16 had possible paraoc- excluding subjects with likely or possible occu- cupational exposure. Table 3 shows the 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% CI) for the OR showed sis. Of the 46 cases, 25 had lived within 0.5 km that data were also consistent with equal odds of any potential source, and 20 in group 1 had of paraoccupational exposure. lived within 0.5 kun of a potential source. The Only 27 matched sets, comprising 34 cases corresponding figures for the 1 17 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 lived 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 controls 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 walls 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 Routes of asbestos exposure and the development of mesothelioma 407 Table 4 Main route of exposure for cases and controls (n(%)) Category Description Cases Controls Total Occupational Likely or possibly occupationally exposed 150 (82) 80 (50) 230 (67) Paraoccupational Likely or possibly paraoccupationally exposed and not occupationally exposed (likely or possible) 17 (9) 14 (9) 31 (9) Incidental Likely or possible incidentally exposed but not occupationally or paraoccupationally exposed (likely or possible) 2 (1) 8 (5) 10 (3) Residential Likely residential exposure to any source but not occupationally, paraoccupationally, or incidentally exposed (likely or possible) 6 (3) 14 (9) 20 (6) None or unknown Subjects not thought to be exposed to asbestos by any of the above routes (this will include subjects whose exposure history has missing information) 10 (5) 43 (27) 53 (15) Total 185 (100) 159 (100) 344 (100) 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.7 These assumed that 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 paraoccupational, 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 that made asbestos slate board, and near an number of cases and controls in each of these. asbestos-cement plant,' '4 but in general, little Occupational exposure was the most common is known about the likely increase in airborne route in both cases and controls. Only 5% of asbestos concentrations near factories that cases seemed to have no exposure to asbestos, used asbestos, or about the area over which this whereas the figure was 27% for the controls. increase might be expected. Given the established risks of occupational Discussion and paraoccupational exposure, a major focus The hazards of occupational exposure to of our study was the hypothesis that living in asbestos have been documented for decades. the vicinity of a factory that used asbestos is a Wagner et aP first established the link between risk factor for mesothelioma. No study has working at, or in close association with, an looked at residential exposure so comprehen- asbestos mine and development of mesothe- sively. Many potential industrial sources of lioma, and subsequent papers have described asbestos were identified in the study area, as the risks associated with other occupations. Of well as the sources which provoked public and study cases 82% had likely or possible occupa- media concern. However, only a few sources tional exposure, compared with 50% of the were near the residences of study subjects, and controls. Comparisons with other case-control very few after the exclusion of subjects with studies are complicated by differing occupa- occupational and paraoccupational exposure. tional coding schemes, but there were similar There were more subjects with occupational or proportions of occupational exposure in the paraoccupational exposure than expected from cases and controls in a North American study other studies: this may be because there was (70% and 51% respectively),10 and fewer so genuinely more exposure by these routes in exposed in a London study (41% and 1 1 %). " Yorkshire in the study period, or because we Our study confirmed that the odds of having a obtained more complete exposure histories, or likely or possible occupational exposure to differences in definitions. We had assumed that asbestos are significantly higher in cases than one third of the cases would have been controls. unexposed through occupational or paraoccu- It is generally accepted that there is a link pational routes, but the actual figure was 9.7%, between paraoccupational exposure to asbestos leaving relatively few cases available for that and mesothelioma. Case-control studies in part of the study that concentrated on residen- London," New York,'2 and North Americal0 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 cases 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 of asbestos 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 close to a living 1.2 km from an asbestos factory, and no source may mean that the subject often walked controls nearby.'2 The North American study past it, or played in the factory yard, etc. Also, found that one case and four controls had lived the identified sources carried out a wide range within 20 miles of chrysotile mines.'0 A of industrial activities with asbestos; some were Connecticut study found that 9.2% of cases known to process large amounts of raw fibre, 408 Howel, Arblaster, Swinburne, Schweiger, Renvoize, Hatton whereas others may only have stored asbestos This case-control study has brought together 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 the risks asbestos industry may be insufficiently precise. of occupational and paraoccupational expo- If residents in the vicinity of some of the 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 km, 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 asbestos. However, more detailed Although heavy exposure through the manu- information about the manufacturing proc- facture of asbestos products has fallen over the esses at the various factories is rarely available, years, there is still scope for exposure in work- preventing more precise estimates of their ers engaged in repair, renovation, and demoli- potential for releasing asbestos into the envi- tion of buildings containing asbestos, the so ronment. Nor was it possible to determine called "third wave of asbestos disease".'7 which type of asbestos was used in many facto- Prevention requires rigorous enforcement of ries, although the Leeds factory, which had existing legislation, workforce education, and provoked concern, was known to use mainly surveillance to ensure that existing standards crocidolite, and the Calderdale factory used are adequate to identify other potential causes crocidolite and brown asbestos (amosite) for of mesothelioma. Only 3% of the cases were long periods.6 15 associated solely with residential exposure, and This and other case-control studies suffer it is not possible to conclude from this study from the fact that retrospective asbestos expo- sure histories are likely to be incomplete: rela- alone Whether such exposure is a risk factor for tives providing information may not be aware development ofmesothelioma. A larger study is of, or be able to recollect, important occupa- needed to do this. It is important that all possi- tions or residences, particularly if these were of ble sources of asbestos exposure should be short duration. The quality of information var- considered and thoroughly investigated in ied: some informants were able to provide very cases of mesothelioma. For instance, 25 of the detailed life histories, others were vague about cases of mesothelioma in Leeds between 1971 particular periods or aspects of the subject's and 1987 were labelled as due to environmen- life. tal exposure to asbestos by Her Majesty's There are also difficulties in trying to ascer- 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 paraoccupationally one route. For example, whereas a weaver of exposed.'8 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 of residential exposure in the development of as the result of living near an asbestos factory, mesothelioma in the community could be or from a family member working there. We reconsidered. have assumed that occupational exposure dominates that from other sources in this study. The few studies which have measured airborne We are particularly grateful to the contacts of the cases of mes- othelioma and those who acted as controls, for their help and asbestos concentrations in non-occupational interest; and to Dr Philip E da Costa, consultant pathologist, settings indicate that paraoccupational expo- Seacroft and Killingbeck Hospital, for carrying out histological confirmation of the cases. We also acknowledge support given sure can lead to higher concentrations than by staff at local pathology laboratories and medical records residential exposure'6, but we cannot be sure departments, staff at local offices of Her Majesty's Coroner and that this is the case for all the subjects in this staff at the University of Leeds Medical Library, Leeds City Library, and Bradford City Library. The study was funded by study. the Colt Foundation. There are no conflicts of interest. Appendix 1: List of jobs that determined the classification of subjects into each occupational class 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, fitter 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 work 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, Routes of asbestos exposure and the development of mesothelioma 409 joiner, laundry worker (ironing), maintenance work, metal worker, munition worker, painter, railway worker, scaffolder, stonemason, tank gunner, telephone engineer, welder. UNLIKELY Baker, barman, catering, cinema manager, cleaner, 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 2: Activities at potential industrial sources of asbestos near Yorkshire residences of study subjects Number of sources within 0. 5 km of 3 1 study subject Group 1-likely manufacture using asbestos: Asbestos goods manufacturers 17 Engine packing, steam packing, or metallic packing manufacturers 13 Brake and clutch manufacturers 7 Jointing and gasket manufacturers 1 Railway carriage and locomotive manufacturers 7 Insulation, boiler covering, or packing manufacturers 1 Fibrous plaster or fibrous cement manufacturers 9 Group 2-may be storage only, or asbestos not used: Asbestos building materials, asbestos cement, asbestos roofing 10 Insulation specialists, engine packing, fireproofing, steam products manufacturer 18 Total 83 1 Talcott JA, Antman KH. Asbestos related malignancy. Current 10 McDonald AD, McDonald JC. Malignant mesothelioma in problems in cancer. Chicago year book. Chicago: Medical North America. Cancer 1980;46:1650-6. Publishers, 1988. 11 Newhouse M, Thompson H. Mesothelioma of the pleura 2 De Klerk NH, Armstrong BK. The epidemiology of asbes- and peritoneum following exposure to asbestos in the Lon- tos and mesothelioma. In: Henderson DW, Shilkin KB, don area. BrJInd Med 1965;22:261-9. Langlois SL, Whitaker D, eds. Malignant mesothelioma. 12 Vianna NJ, Polan AK. Non-occupational exposure to asbes- New York: Hemisphere, 1992:223-50. tos and malignant mesothelioma in females. Lancet 1978;i: 3 Polnar PV. Further evidence of non-asbestos related 1061-3. mesothelioma. A review of the literature. Scand Jf Work 13 Lebel. Review offibre concentrations in Quebec asbestos mining Environ Health 1988;14:141-4. towns. Quebec: Quebec Asbestos Mining Association, 4 Peto J, Hodgson JT, Matthews FE, Jones JR. Continuing 1984. increase in mesothelioma mortality in Britain. Lancer 1995; 14 Kohyama N. Airborne asbestos levels in non-occupational 345:535-9. environments in Japan. In: Bignon J, ed. Non-occupational 5 Gardner MJ, Acheson ED, Winter PD. Mortality from mes- exposure to mineralfibres. Lyon: IARC, 1989:262-76. othelioma of the pleura during 1968-78 in England and 15 Edward AT, Whitaker D, Browne K, Pooley FD, Gibbs AR. Wales. BrJ Cancer 1982;46:81-8. Mesothelioma in the north of England. Occup Environ Med 6 Arblaster L, Hatton P, Renvoize ER, Schweiger MS. Leeds mesothelioma deaths 1971-87. Leeds: Leeds Western Health 1996;53;547-52. Authority, Leeds Eastern Health Authority, and Leeds City 16 Nicholson WJ, Rohl AN, Weisman I, Selikoff IJ. Environ- Council, January 1990. mental asbestos concentrations. In: Wagner JC, ed. Biologi- 7 Teta MJ, Lewinsohn HC, Meigs J, Wister V, Romeo A, cal effects of mineralfibres. Lyon: IARC, 1980:823-7. Mowad LZ, et al. Mesothelioma in Connecticut, 1955-77. 17 Landrigan P. The third wave of asbestos disease: exposure to J Occup Med 1983;25:749-56. asbestos in place [preface]. Ann New York Acad Sci 8 Collett D. Modelling binary data. London: Chapman and 1991;643:15-6. Hall, 1991. 18 Arblaster L, Hatton P. Howel D, Renvoize E, Schweiger M, 9 Wagner J, Sleggs C, Marchand P. Diffuse pleural mesothe- Swinburne LM. Occupational and environmental links to lioma and asbestos exposure in the North Western Cape mesothelioma deaths occuring in Leeds during 1971-87. J Province. BrJ7Ind Med 1960;17:260-71. Public Health Med 1995;17:297-304.
Pages to are hidden for
"Routes of asbestos exposure and the development of mesothelioma "Please download to view full document