Document 9L0pozqBDaexekkwxK6GMOmB3

FILE NAME Brakes BRK DATE 2009 DOC BRK204 DOCUMENT DESCRIPTION Journal Article - Occupational Domestic and Environmental Mesothelioma Risks in the British Population British Journal of Cancer 2009 100 1175-1183 '2009 Cancer Research UK All nights reserved 0007 0920/09 32.00 mpg ww.bjcancer.com www.bjcancer.com re Occupational domestic and environmental mesothelioma risks in the British population a control study C Rake C Gilham J Hatch A DarntonJ Hodgsonand J Peto Institute of Cancer Research Sutton Surrey SM2 5NG UK Epidemiology Unit Health and Department of Epidemiology and Population Health London School Safety Executive Bootle Merseyside L20 3QZ UK 7HT UK of Hygiene and Tropical Medicine London University Keppel Street London WCIE We obtained lifetime occupational and residential histories by telephone interview with 622 110 women and 1420 population controls Odds ratios mesothelioma patients 512 men 1940s Male ORs ORs were converted to lifetime risk LR estimates for Britons bom in the 95 confidence interval CI relative to lowrisk occupations for > 10 of years were 50.0 25.8-96.8 for carpenters LR in 17 years exposure 17.1 10.3-28.3 for plumbers electricians before the age of 30 other construction workers 15.3 9.0-26.2 for other recognised and painters 7.0 3.2-15.2 for asbestos be recognised high occupations and 5.2 3.1-8.5 3.1-8.5 in other industries where may encountered The LR was similar in apparentlyapparently apparently unexposed men and women ~ 1 in 1000 and this approximately doubled in exposed workers relatives OR 2.0 95 % CI 1.3-3.2 No other environmental hazards was identified In all 14 of male and 62 of female cases were not attributable to occupational or domestic asbestos were of the male cases were construction workers and only four had workedworked for more than 5 exposure Approximately half British Joumal of Cancer 2009 100 1175-1183 doi 10.1038 years in asbestos product manufacture ~ Published online 3 March 2009 sj.bjc.6604879 www.bjcancer.com '2009 Cancer Research UK Keywords mesothelioma control amosite The British mesothelioma death rate is now the highest in the world with 1749 deaths in men 1 in 40 of all male cancer deaths below 80 years of age and 288 in women in 2005. The projected lifetime risk LR of fatal mesothelioma in all British men born in the 1940s is 0.59 Hodgson et al 2005 or about 1 in 170 of all deaths Substantial exposure to asbestos dust continued until about 1970 in parts of the asbestos industry and until the early 1980s in the much larger workforce in construction and other occupations in which asbestos lagging was applied or asbestos insulation board AIB was sawn The death rate is still above 60 years of age but the reduction in asbestos useinscirnecaestihneg 1970s has been followed 20 years later by a rapid fall in the number of mesothelioma deaths at 35-49 years of age in British men 289 in 1990-1994 122 in 2000-2004 2000-2004 2000-2004 although less in women 56 in 1990-1994 39 in 200020 -2-04 220000-020404 Earlier control studies have used hospital controls or relied on next interviews and most involved small numbers of cases Muscat and Wynder 1991 Howel et al 1997 Teschke et al 1997 Iwatsubo et al 1998 Agudo et al 2000 Rodelsperger et al 2001 We carried out the first population- based study in Britain of the relationship between mesothelioma risk and lifetime occupational and residential history of asbestos exposure obtained at interview and the largest worldwide The main aim was to estimate risks and numbers of cases caused by specific occupational and environmental exposures The results are particularly relevant to developing countries where uncontrolled asbestos exposure is still common Correspondence Professor| Peto mail Julian.Peto@lshtm.ac.uk Julian.Peto@lshtm.ac.uk Received 30 September 2008 revised 15 December 2008 accepted 15 December 2008 published online 3 March 2009 MATERIALS AND METHODS Mesothelioma patients in England Wales and Scotland born since 1925 were identified through chest physicians surgeons and nurses the National Cancer Research Network and English and Scottish hospital records A small proportion was identified through cancer registries and other sources Population controls were selected at random from a 1 in 300 sample from Health Authority registers now Primary Care Trusts frequency matched by year age group and sex Owing to fears of legal liability under confidentiality and data protection law no data were provided by any of the Health Boards in Scotland 11 Health Authorities in England and 3 in Wales Up to six randomly selected matched GP controls were approached for each interviewed mesothelioma case in these areas The study was approved by the South Thames MREC Overall 39 of 1396 notified mesothelioma patients 423 too ill or dead 87 no GP or consultant permission and 31 ineligible or not traced and % of 2897 controls 169 too ill or dead 169 no permission 191 ineligible or untraced were not invited for interview The proportion of those invited who were interviewed sometimes after several reminders consisted of 73 624 out of 857 of mesothelioma cases and 60 1420 out of 2368 of controls As expected response rates in controls were higher in more affluent areas 69 in the top two quintiles of socioeconomic that status and 46 in the lowest There was no evidence construction workers were under ascertained with 8.3 of building controls classified as working in skilled construction and trades and 1.8 as carpenters compared with 2001 census proportions of 6.5 and 1.7 respectively The study was initially restricted to cases born since 1940 later extended to 1925 to include those aged up to 80 years This resulted in a higher 1176 Table I UK mesothelioma control study C Rake et al Interviewed mesothelioma cases and controls by job category and all British mesothelioma deaths by year of birth and sex Mesothelioma cases Population controls National mesothelioma register 2000-2004 Year birth Central age Male cases 1965 324056527 1960 1964 324056527 1955 1959 324056527 1950 1954 324056527 1945 1949 324056527 1940 1944 324056527 1935-1939 324056527 1930-1934 324056527 1925-1930 324056527 Ever worked in high jobs Never worked in high jobs Total Ever worked in high >" > jobsb Never worked in high jobs | 4 11 42 105 145 82 48 36 -0247 2 0.4 | -022407 4 0.8 5 -022407 13 2.5 20 -02 407 44 8.6 66 -022407 119 23.2 162 10 155 303 252 -022407 89 17.4 97 H 49 9.6 52 1 37 72 44 3 7 16 NANNA 123 128 46 NANNA 18 Total 3 13 36 Hi 285 380 143 79 62 % n 03 3 1.2 14 32 48 100 166 256 524 342 129 1223 7 1420 5.6 1529 % 01 02 08 29 9.0 153 21.0 244 263 Total Female cases 2 1965 305050322 1960 1964 305050322 1955 1959 45 1950 1954 305050322 1945 1949 305050322 1940 1944 305050322 1935 1939 305050322 1930-1934 70 1925-1930 75 474 0-263852 0 -263852 0-26385 0 -263852 0 -263852 13 0 -263852 0 -263852 0 -263852 38 512 100.0 699 2-75-2 2187 1.8 02-702na 2-752 2187 0.9 02-702na 2-75-2 2187 73 02-7na 2-75-2 2187 6.4 02-702na 2-75-2 17 155 02-702na 21 34 30.9 02-702na 17 25 22.7 02-702na ^^ 12 10.9 02-702na ~ 4 3.6 4 413 0 4 13 13 45 75 55 21 1112 1000 = 5820 ODIGYN ODIGYN 1.9 ODIGYN 45 ODIGYN 6.5 ODIGYN 175 ODIGYN 299 77 250 30 97 15 49 5 5 23 31 86 162 181 178 230 1000 06 C.6 26 3.4 95 180 201 201 198 255 Total 37 73 110 100.0 71 237 308 1000 = 901 1000 In all 97 601 out of 622 of cases were diagnosed between 2000 and 2004 Ever worked in job categones 1-5 1-5 construction high carpenter electrician painter other construction and medium industrial jobs Worked only in nsk industnal or industrial jobs proportion of younger cases Histological confirmation was mesothelioma cases than seen nationally Table ) obtained for 92 of interviewed Interviews were conducted between January 2001 and June 2006 Cases and controls were ineligible if they were physically or mentally unfit for interview without access to a telephone or unable to speak English All eligible patients were sent a preinterview postal questionnaire requesting lifetime occupational and residential history This formed the basis for the structured telephone interview which also included questions on smoking history DIY activities and other possible environmental exposures Cases were asked about various asbestos exposures in each job depending on the type of work These included work with AIB lagging sprayed coatings cement insulation protection materials gaskets textiles and brake linings For each job the duration description and occupational code were recorded together with frequency of direct or bystander asbestos exposure Statistical methods Odds ratios ORs adjusted for year period of birth and socioeconomic status quintile of Townsend score from 2001 census data linked to postcode were estimated by unconditional logistic regression analysis using STATA StataCorp 2007 Occupational histories were truncated in 1992. Occupations were assigned to risk categories primarily on the basis of proportional mortality ratios PMRs for mesothelioma McElvenny et al 2005 construction high occupations most with > PMR 200 included asbestos factory workers laggers shipbuilding and dockyard workers naval personnel and others working on board ships Preliminary analysis showed that the risk was highest for carpenters and higher for plumbers electricians and painters than for other construction workers All other jobs were classified on the basis of Standard Occupational Classification 1990 code and main place of work as medium industrial primarily occupa- tions with > PMR 100 including mechanical and electrical process and assembly workers welders railway workers surveyors inspectors and industrial scientists risk industrial including motor mechanics draughtsmen warehousemen drivers plant and machine operators and armed forces or industrial Substantial asbestos exposure was defined as working with or disturbing AIB sprayed coatings lagging other asbestos insulation or raw asbestos Cases were thus classified into eight mutually exclusive exposure groups based on their highest exposure category irrespective of duration These were ranked as ) highrisk including lagging and shipbuilding but excluding construction 2 carpenter 3 plumber electrician painter 4 other construction 5 medium industrial 6 substantial asbestos exposure in a risk occupation 7 living with an occupationally exposed relative and 8 the remainder comprising 52 cases 18 men 34 women and 439 controls 289 men 150 women with none of these exposures Men who worked only in risk industrial or industrial jobs groups 6 7 and 8 constituted the reference group for the occupational analyses in Tables 3-5 Univariate analyses of domestic and neighbourhood exposures and work with other asbestos products protection materials gaskets and brake linings were restricted to cases who had only done risk industrial or industrial work not involving substantial exposure groups 7 and 8 Possible occupational hazards included living with an asbestos worker or in a council property prefab or high block living near a potentially hazardous site asbestos factory or disposal site power plant and British Journal of Cancer 2009 100 1175-1183 '2009 Cancer Research UK shipyard and DIY involving asbestos A full report giving details of the occupational classifications and subgroup results will appear on the Health and Safety Executive's website www.hse.gov.uk Lifetime risks in men were calculated from ORs as OR where A is 0.59 the predicted lifetime mesothelioma risk in British men born in the 1940s Hodgson et al 2005 and B is the weighted average OR in male controls B equals 7.4 in Table 6 where the reference group is unexposed and 5.0 in Tables 3-5 where the reference group includes men who reported domestic exposure or substantial occupational exposure in risk jobs RESULTS Occupational exposure Those interviewed 622 mesothelioma cases and 1420 controls are shown by sex period of birth and exposure category never worked in job groups 1-5 in Table 1. The occupational analyses in Tables 2-5 are restricted to men Figure 1 shows the proportions of male cases and controls beginning a new job in each period since 1940 who reported asbestos exposure in that job Jobs of more than 5 years duration are excluded to ensure that reported exposure is representative of the period when the job started The frequency of exposure fell sharply during the 1970s and the heaviest exposures sawing AIB or applying lagging or sprayed coatings had virtually ceased by 1982. The hand part of Table 2 shows ORs for male mesothelioma cases and controls who worked for at least 5 years in each main job group Forty of the 102 construction high mesothelioma cases had worked in docks shipyards or on naval ships and 26 in the Navy The reference group in Table 2 comprises 25 cases and 278 controls with no high- or medium or construction work and less than 5 years in risk industrial occupations Carpenters suffered the highest risk OR 36.0 95 confidence interval CI 19.2-67.3 followed by all construction high jobs OR 16.8 95 CI 9.6-29.3 plumbers electricians and painters OR 14.6 95 CI 8.8-24.4 and other construction workers OR 7.9 95 CI 4.7-13.3 The overall OR for 5 or more years in any medium The hand part for men who never industrial job was 5.2 95 CI 3.3-8.2 of Table 2 shows the corresponding ORs worked in any higher risk category The ORs for construction and medium industrial workers remain high when those with higher risk occupations are excluded In contrast the OR for risk industrial occupations falls from 4.1 95 CI 2.6-6.4 overall to 1.1 95 CI 0.5-2.2 UK mesothelioma control study C Rake et al 1177 when those who had also worked in medium or higher risk jobs are excluded Table 3 shows ORs for men ever employed as carpenters lower part or in at least one high construction or medium job upper part by age starting the first such job and duration of relevant employment The OR in men first exposed before the age of 20 years is 13.4 95 CI 9.2-19.6 for 20 or more years of any high work and 99.7 95 CI 43.7-227.5 for 20 or more years as a carpenter Analyses of duration before and after 30 years of age for all high work Table 4 upper part and for carpentry lower part show a strong trend in OR with increasing duration only before 30 years of age Odds ratios are consistently lower in each row in men who stopped exposure before 30 years of age but there is no evidence of increasing risk with longer duration after 30 years and the OR for men first employed in any high job after 30 years was only 1.7 95 CI 0.7 3.9 In Table 5 men are assigned to the five occupational groups on the basis of the highest category in which they ever worked see Materials and Methods As in Tables 3 and 4 ORs are relative to men employed only in risk industrial or industrial jobs The ORs and corresponding LRs for 10 or more years of relevant work before 30 years of age were highest for carpenters OR 50.0 LR 5.9 about third as high for electricians plumbers and painters OR 17.1 LR 2.0 and for construction high jobs OR 15.3 LR 1.8 and lower for other construction workers OR 7.0 LR 0.8 and for all medium industrial jobs OR 5.2 LR 0.6 Odds ratios for all men in each category irrespective of duration are also shown ranging from 23.3 for carpenters to 2.8 for medium industrial workers The nature and frequency of reported substantial asbestos exposure were also predictive with higher risks in each category in men reporting frequent direct exposure but the OR was still significantly increased within each of the five exposure categories Table ) among men who did not report direct or indirect substantial exposure in any job before 30 years of age The proportion of controls reporting direct exposure before 30 years of age was 67 28 out of 42 among carpenters 55 63 out of 114 among plumbers electricians and painters 26 37 out of 142 among other construction workers 12 32 out of 263 among medium industrial workers and % 12 out of 413 among risk workers occupational exposure The reference group in Tables 3-5 included 33 men 7 cases 26 controls who reported substantial asbestos exposure in low- Table 2 Numbers of male mesothelioma cases and controls who worked for at least 5 years before 1992 in each occupational category Occupational category Cases Controls OR 95 Cls Cases Controls OR 95 CIs Non construction high risk Any construction high job 102 Construction Carpenter 93 Plumber electrician painter or decorator 115 Other construction 81 78 168 96 29.3 No other high work Now 360 192 673 673 81 30 96 14.6 88 244 99 82 Now 7.9 133 59 101 393 202,765 202,765 14.8 87 25.1 68 40,117 40,117 Medium industrial Any medium industnal job No high or construction work 157 331 5.2 3.3 8.2 57 201 19,53 Low nsk industrial Any nsk industrial job Reference group No high risk construction or medium risk work 153 406 4.1 26.6.4 26.6.4 13 135 1 22 25 278 1.0 ref 25 278 10 Abbreviations CI confidence interval OR = odds ratio Men with any exposure in preceding occupational categories are excluded in the hand part of the table reference group worked only in industnal jobs or in risk industrial jobs for less than 5 years The '2009 Cancer Research UK British Jouma of Cancer 2009 100 1175-1183 upg 1178 UK mesothelioma control study C Rake er al Table 3 Odds ratios for male cases by age started and total duration in nsk"occupations and in carpentry Duration of employment 5 years Age at first job of this type Cases controls All high risk jobs OR 95 CI 5-9 years Cases controls OR 95 CI 10-19 10-19 years Cases controls OR 95 CI 20 years Cases controls OR 95 CI Total Cases controls OR 95 CI 20 20-29 30 Total Carpentry 27/75 7/41 5/15 39/131 40 2.3 6.9 18 0.8 4.4 36 12 10.4 3.2 2.0 36/77 3/16 016 39/99 5.2 3.1 8.7 2.0 06 7.3 0.0 0.0 7.1 2.6,72 51/93 7/37 2/23 60/153 5.9 3.6 96 2.1 09,50 09,50 1.0 02 43 4.2 6.6 311/265 24/46 1/5 336/316 13.4 9.2 55 3.0 18 0.2 .2.1 83 196 101 163 17.6 425/510 41/140 8/49 474/699 92 6.4 131 3 19,50 17 0.7.39 0.7.39 51.104 51.104 20 20 7/9 90 3.0 264 617 100 3.0 33 14/5 38.9 124.122.1 63/10 99.7 5/4 213 4.8.93.4 4.8.93.4 2/3 9.3 7,227 5 90/3 380 2.3 2.3 67.5 Total 12/13 270 8/10 1.4 619 92 259 316 17/11 55 13.245 13.245 18.5 7.8 44.1 5/5 68/15 11.0 29.41.1 29.41.1 625 15/18 100 46.219 30.9.1265 105/49 265 159.442 159.442 = Abbreviations Cl confidence interval OR odds ratio Odds ratios are relative to the 38 High risk includes job categones 1-5 construction cases and 413 controls with no high construction or medium industrial high carpenter electrician other construction and medium industrial jobs Cornfield confidence interval jobs Unadjusted Table 4 Odds ratios for male cases by duration of employment in nsk"occupations and in carpentry before and after 30 years of age Duration after 30 years of age None 10 years 10 years Total Duration before 30 years of age All nigh jobs Cases controls OR 95 CI Cases controls OR 95 CI Cases controls OR 95 CI Cases controls OR 95 CI None 10 years > 10 years Total 59/163 19/31 78/194 39 2.5.6.1 2.5.6.1 6.8 35. 13.3 4.4 28.6.7 28.6.7 5/21 27176 54/53 86/150 25 0.9 6.8 39 22 6.8 11.5 69 19.1 62 4.1.96 4.1.96 3/28 47/104 260/223 310/355 1.1 0.3.38 0.3.38 4.7 29.77 13.1 8.9 193 9.6 66 14.0 8/49 133/343 333/307 474/699 17 07,39 07,39 4.1 28,6.1 28,6.1 21 84,176 84,176 73 51 104 Carpentry None 10 years > 10 years Total 16/16 7/3 23/19 Abbreviations Cl = confidence interval High risk includes job categones 1-5 114 114 5.1 25.6 26.3 6.3,1097 6.3,1097 134 6.5 27.6 3/7 6/1 12/2 21/10 6.5 1.5 28.0 58.3 6.4 532.1 93.1 18.9 458.3 28.1 11.6 678 2/4 816 51/10 61/20 70 12 42.2 151 151 48 47.2 73.8 32.3 168.9 409 213,788 213,788 213,788 5/11 30/23 70/15 105/49 66 2.1.210 2.1.210 146 7.6 283 663 325 1355 265 159,442 159,442 = OR odds ratio Odds ratios are relative to the 38 cases and 413 controls with no high construction or medium industrial jobs construction high carpenter electrician other construction and medium industrai jobs risk occupations These were excluded in univariate analyses of other and occupational exposures which were restricted to substantial men 31 cases 387 controls and women 71 cases 236 controls who reported no high- or medium work and no exposure in any job Other potential asbestos exposures at work were not associated with significantly increased risk although few were reported These included vehicle maintenance involving work with brakes or gaskets OR 0.4 95 CI 0.1-1.7 0.1-1.7 asbestos present at the workplace OR 0.8 95 CI 0.5-1.5 construction work at the workplace OR 1.4 95 CI 0.8-2.3 working in or near a shipyard or construction site OR 1.3 95 CI 0.3-6.1 and any other reported asbestos exposures at work OR 1.6 95 CI 0.7-3.6 0.7-3.6 0.7-3.6 The only significant occupational association was living with a potentially exposed worker before 30 years of age OR 2.0 95 CI 1.3-3.2 The OR for living within a mile of a potential source before 30 years of age asbestos factory or disposal site shipyard or power plant was 0.6 95 0.2 2.00.2 2.0The OR for any type of DIY activity was 0.7 0.4-1.2 0.4-1.2 and no subgroup of DIY activity by frequency or possible asbestos exposure suggested any excess No type of housing was significantly associated with risk prefab council or former council high rise or any asbestos in the building The OR for current smokers compared with non- Bnt.sh Journal of Cancer 2009 100 1175-1183 smokers was 1.5 95 CI 0.8-2.7 in this unexposed subgroup and 1.2 95 CI 0.9-1.6 overall Asbestos and background cases All men and women are shown in the eight overlapping exposure categories see Materials and Methods in Table 6. Cases are classified by their highest exposure so the groups are mutually exclusive The reference group for this analysis comprises the 52 cases 18 men 34 women and 439 controls 289 men 150 women with none of these exposures Five of the 110 female cases reported high work OR 4.8 95 CI 1.3-17.7 A further 32 only female cases had done medium industrial work OR 2.4 95 CI 1.3-4.3 the majority 88 as assemblers or routine process operatives The risk was also increased in those who worked in risk jobs but reported a substantial asbestos exposure seven male and two female cases combined OR 3.8 95 CI 1.78.8 The ORs for domestic exposure before 30 years of age in Table 6 2.1 for men 1.9 for women combined OR 2.0 95 CI 1.3-3.2 are based on cases with no occupational exposure Logistic regression analysis in all cases adjusting for duration and main exposure group gave an OR for domestic exposure before 30 '2009 Cancer Research UK UK mesothelioma control study C Rake et al Table 5 Odds ratios for male cases by duration of employment before 30 years of age for job category and reported asbestos exposure Duration in job category before 30 years of age None controls OR 95 CI < years controls OR 95 CI 5 9 years controls OR 95 CI 10 years controls OR 95 CI Lifetime risk for 10 years duration construction high risk 4/15 2.8 0.9.8.9 0.9.8.9 Carpenters 3/10 31 0.8,118 0.8,118 52/59 9.8 5.9 162 9/12 8.2 3.2 209 42/25 18.3 10.0 33.7 11/5 24.4 8.0 749 55/39 153 9.0.26.2 9.0.26.2 1.8 66/15 50.0 25.8 96.8 5.9 Construction Plumbers electricians painters Other construction 6/12 5.2 1.8 14.9 7/24 3.2 3,81 13/34 40 19,8.3 19,8.3 20/66 3.3 1.8 6.0 24/22 123 6.3 24.2 12/30 4.3 20,90 20,90 69146 17.1 10.3 283 283 20 13/22 7.0 32 15.2 0.8 All other jobs Medium industrial Low risk ref 4/26 15 05,46 05,46 15/79 21 11.40 8/68 12 06,28 06,28 4 190 52 31,8.5 06 012 upg 1179 Reported asbestos exposure before 30 years of age None controls OR 95 CI 29/56 55 31,97 Indirect < years controls OR 95 CI > years controls OR 95 CI 5/14 4.0 13.117 23/11 217 9.7 48.5 12/12 9.8 4.1 23.5 2/1 168 14 1960 1/1 10.2 0.6 171.2 16/38 4.4 2.2 8.7 2/4 5.0 09. 28.9 15/9 183 74 44.9 23/91 27 1.5 4.8 35/202 11,31 33/393 4/6 4116 1/1 7.6 2.0 28.5 25 08.79 4/8 6/13 117 61 17,214 17,214 47 17132 17132 Direct infreq < years controls OR 95 CI > years controls OR 95 CI 10/6 180 61.53.2 61.53.2 20/16 135 64.285 64.285 TI 12.1 4.9 300 32/8 49.6 21.1.116.4 21.1.116.4 5/19 2.9 1.0 8.2 39/25 17.4 95 32.0 2/7 8 0/4 3.0 06 151 12 0.9.8 8/17 11,18 1/7 5.5 2.2 136 69 30.158 30.158 Direct freq < years controls OR 95 CI > years 26/13 22.3 10.5 474 12/4 32.0 9.7 1055 1055 617 9.5 3.0 29.9 4/7 2/1 1/1 6.4 1.8 23.0 224 19 2613 2613 controls OR 95 CI 40/22 19.2 10.2 36.1 19/5 38.4 135 109.6 29/12 275 12.9.586 12.9.586 716 9/5 1/0 110 34.349 34.349 20.7 65 65 Ever worked in job category controls OR 95 CI 153/138 11.9 7.9 18.0 89/42 233 141 38.5 112/114 10.8 7.1 16.5 52/142 4.0 25,64 25,64 68/263 28 18 43 38/413 10 ref -50 oddsType Abbreviations confidence interval OR ratio Cases who ever worked in each job category are excluded in 90 = OR ^ 059 -50 See statistical methods and duration of asbestos subsequent columns Projected lifetime risk to age these are coded hierarchically Work done by someone in the exposure in any job category Groups are mutually exclusive that is if severa Work exposures occur weekly same area done themselves less than once per week Work done themselves at least years of age of 2.3 95 CI 1.5-3.8 in women significantly higher than the OR of 1.1 95 CI 0.9-1.4 0.9-1.4 in men Similar analyses based on the type of relative irrespective of age gave a combined estimate of 1.3 95 CI 1.0-1.6 1.0-1.6 for living with a high parent or sibling and an estimate of 2.1 1.3-3.5 for living with a highrisk spouse The latter was based largely on women as only two male cases and one male control reported living with a high spouse Of controls 20 reported living with a high parent and 12 with a high sibling and 20 of female controls had lived with a high spouse Table 6 shows the attributable fraction of cases in each category ranging from 97 86.4 out of 89 among male carpenters to 49 exposed 24.3 out of 50 in men and women who lived with an worker before 30 years of age In all 85 435.6 out of 512 of male and 22 24.5 out of 110 of female cases are attributed to occupational exposure and a further 1.3 6.8 out of 512 of male occupational and 16 17.5 out of 110 of female cases had no exposure but were attributed to living with a high worker The total number of unattributed background cases is 69.6 in men and 68.0 in women '2009 Cancer Research UK British Journal of Cancer 2009 100 1175-1183 1180 5 45 UK mesothelioma control study C Rake er al 404 354 30. 25 4 % 204 All asbestos exposures a -Cases sss Controls 154 10 5 a, a a * - Applying AIB or * lagging - . 7s sae ie) 1940 1943 Cases Controls 34 18 39 1946 38 67 1949 48 93 1952 73 130 1955 100 + gO T r T T r t i i T ae 1958 1961 1964 1967 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 178 187 292 301 326 143 313 287 110 257 204 167 80 130 140 56 144 50 72 102 Figure | Proportion of all men reporting asbestos exposure by year starting new job Year starting job 3 year period Table 6 Mesothelioma cases in men and women attributed to asbestos exposure in each exposure category Male cases Female cases Cases Cases Highest exposure category Occupational exposure construction high risk Carpenters Plumbers electricians and painters Other construction Medium industrial Other substantial exposure occupational exposure Domestic exposure before 30 years of age None of the above reference Attributed to this exposure Yes 1443 86.4 105.0 43.2 514 5.3 68 No" Total Controls OR 95 CI 87 2.6 7.0 88 16.6 1,7 153 89 112 52 68 7 138 42 114 142 263 26 17.5 10.3 29.8 34.2 187 626 159 92 273 59 33 10.5 41 24 7.2 4.2 16 109 62 18.0 13 98 21 1.0 4.5 18 289 1.0 Attributed to this exposure Yes 4.0 _ _ 187 1.8 175 No" Total Controls OR 95 CI 1.0 SOO 5 177 SOO _ 0 _ - SOO 2 ~ ~- 0NN I ~ 13.3 32 63 13.43 13.43 0.2 2 { 9.6 0.8 112.3 195 34.0 37 86 19 11,32 34 150 10 Tota 442.4 69.6 512 1112 7.4b 42.0 68.0 110 308 16 = Average Abbreviations CI = confidence interval OR = odds ratio Cases in each row are excluded in subsequent rows Number not attributed to of ORS weighted by number of controls in each row exposure tota cases DISCUSSION Proportional mortality ratios for mesothelioma based on last fulltime occupation as recorded on death certificates McElvenny et al 2005 provide the only estimates of occupational mesothelioma risks in Britain The risk depends mainly on asbestos exposure below 30 years of age however Tables 3 and 4 and our British Journal of Cancer 2009 100 1175-1183 study provide the first overview of the distribution of risk in the British population the extraordinary risks suffered by men who did the most dangerous jobs when they were young and the contribution of environmental exposure particularly to the families of exposed structured questions workers Recall bias was minimised by about specific exposures and our main analyses were based on job title which should be less liable to '2009 Cancer Research UK differential response by cases than reported asbestos exposure The value of lifetime job histories is illustrated by men who had worked for at least 5 years in risk industrial occupations their ORs fell from 4.1 95 CI 2.6-6.4 to only 1.1 95 CI 0.5-2.2 when those who had also done more hazardous work were excluded Table 2 Among motor mechanics for example only 2 of 18 cases compared with 23 of 54 controls had never worked in other more hazardous occupations Of male mesothelioma cases 94 481 out of 512 and 65 725 out of 1112 of male controls had worked in a hazardous occupation Table 6 implying an attributable fraction of 85 The predicted lifetime mesothelioma risk for British men born in the 1940s who did more than 10 years of relevant work before 30 years of age is 5.9 for carpenters 2.0 for plumbers electricians and painters and 0.8 for other construction workers Table 5 The LR is 1.8 for all high construction occupations but this is a broad category that includes many subgroups with substantially higher risks Table 2 shows their overall OR for 5 or more years work which was 16.8 95 CI 9.6-29.3 but the OR for metal plate workers mainly shipbuilders was 43.3 95 CI 13.5 138.6 Although this is the largest published study of mesothelioma risk in relation to lifetime occupational history much larger numbers would be needed to provide reliable estimates for individual occupations The proportion of men who had ever worked in carpentry was % of controls and 21 of mesothelioma cases Table 4 49 out of 1112 controls 105 out of 512 cases and 33 10 out of 30 of mesothelioma cases in men born since 1950 who started work in 1970 or later so the predicted eventual total of 000 mesothe- lioma deaths in both sexes in Britain by 2050 Hodgson et al 2005 will include about 15000 former carpenters The excess lung cancer risk in heavily exposed workers is likely to be of the same order as the mesothelioma risk Darnton et al 2006 so more than 1 in 10 of all British carpenters born in the 1940s may die of a cancer caused by asbestos A substantial proportion of these deaths will be among those who installed AIB as fireproofing required under building regulations HMSO 1965 and these will far exceed any possible benefit of such work to the public The large amount of asbestos that remains in many older buildings is still a potential hazard to construction workers involved in renovation maintenance or asbestos removal The risk to carpenters is particularly high in Britain and also in Australia Yeung et al 1999 Most studies in other countries reported higher risks in plumbers electricians and other construction workers than in carpenters Muscat and Wynder 1991 Teschke et al 1997 Rodelsperger et al 2001 Among construction workers preliminary results of a French populationbased control study show the highest risks in plumbers pipe fitters structural steel workers and construction labourers Goldberg et al 2006 In a large interview study in California based on main occupation of over 2000 mesothelioma cases and plumbers pancreatic cancer controls increased ORs were seen for OR - 4.9 95 CI 2.8 -8.3 electricians OR = 3.8 95 CI 2.0 7.1 and painters OR 95 CI 1.3-5.3 but not for carpenters OR = 1.2 95 CI 0.8-2.0 Pan et al 2005 The ORs within each occupational exposure category were lower but still substantially increased even in men who recalled no substantial asbestos exposure suggesting that many were exposed indirectly or could not identify the asbestos materials they handled Most people report their own and their parents occupations correctly many years later Berney and Blane 1997 but recall of past asbestos exposure shows poor reproducibility at interview Holmes and Garshick 1991 A recent study of plumbers showed that many do not recognise the friable asbestos materials that they still sometimes encounter Bard and Burdett 2007 The increased risk for medium industrial work reflects widespread and often unrecognised contact with asbestos in metal working electrical trades and assembly line work A large UK mesothelioma control study C Rake et al opg proportion of the British population worked in these sectors 24 of male and 20 of female controls There were too few occupationally exposed female mesothelioma cases to estimate risks reliably but Table 6 suggests that workplace exposure caused about 22 24.5 out of 110 of all female cases The occupational hazard in women was concentrated in medium industrial settings particularly assembly line work The only evidence of an occupational risk outside high- or medium and construction occupations was the seven men and two women who reported substantial personal or bystander exposure in other occupations Table 6 1181 occupational exposure The only substantial risk factor in those with no direct occupational exposure was living with a high worker a hazard that has been recognised for many years Newhouse and Thompson 1965 Vianna and Polan 1978 Joubert et al 1991 Bourdes et al 2000 Magnani et al 2001 The excess risk which was confined to those who lived with an exposed worker before 30 years of age and was similar in men and women combined OR 2.0 95 CI 1.3-3.2 corresponds to an increase in LR of about 1 per 1000. There was no overall risk in men and women who reported living within a mile of a potential environmental hazard asbestos factory or disposal site shipyard or power plant before 30 years of age although the risk was significantly increased in those who lived near one of these potential sources for 20 or more years OR 3.3 95 CI 0.7-14.8 0.7-14.8 based on three cases and six controls We had no means of identifying sites that produced substantial local exposure There was certainly some hazard to residents around a few factories in the past Newhouse and Thompson 1965 Magnani et al 2001 but no risk was seen around others Hammond et al 1979 and many apparently environmental cases are related to occupational exposures Arblaster et al 1995 There was no significant difference between current smokers and lifelong nonsmokers either in this apparently unexposed subgroup OR 1.5 95 CI 0.8-2.7 0.8-2.7 or overall OR 1.2 95 CI 0.9 1.6 presumably The unattributed cases in each row of Table 6 are due to ambient or unreported asbestos exposure or to other or natural causes This unexplained risk is similar for industrial including retail office educational health and agricultural and risk industrial work and corresponds to a predicted LR of 0.08 in men The analysis of attributable risk in Table 6 indicates that these background cases accounted for 69.6 14 of the 512 male and 68.0 62 of the 110 female mesothelioma cases The same analysis restricted to cases born during 1940-1949 also gave similar male and female estimates for the number of unattributed cases 31.9 out of 274 in men and 36.7 out of 51 in women Table 1 during shows that the female ratio of interviewed cases born 1940-1949 5.4 1 was close to that of all British mesothelioma deaths during 2000-2004 among those born during 1940-1949 5.7 The annual number of unexplained mesothelioma cases is thus similar in men and women and corresponds to a LR of the order of 1 per 1000 among Britons of both sexes born in the 1940s The cumulative female mesothelioma death by age 70 is now more than three times higher in the UK 0.037 than in the US 0.012 If this is due to differences in asbestos exposure more than two thirds of mesotheliomas in British women born since the 1930s are caused by asbestos far more than the 38 Table 6 42,0 that were attributed to identified exposures in our study A similar conclusion is suggested by the three increase in the death in British women between 1975-1979 and 2000-2004 This would imply that at least 30 of female cases of the order of 100 per year are caused either by environmental asbestos exposure or by occasional or ambient exposure in occupational settings that we have classified as low risk If so there is presumably a similar number in men Many apparently spontaneous mesotheliomas are therefore likely to be due to an '2009 Cancer Research UK British Journal of Cancer 2009 100 1175-1183 UK mesothelioma control study C Rake er al increase in ambient asbestos exposure that coincided with the widespread occupational exposures of the 1960s and 1970s Future trends The upper part of Table 4 shows that high- or medium exposure beginning after 30 years of age did not cause a statistically detectable increase in risk Among men already exposed for 10 or more years before 30 years of age however a further 10 or more years of exposure after 30 years of age increased the OR from 6.8 to 13.1 for all high work The estimated factor is 2.1 95 CI 1.1-4.0 in an analysis restricted to these two subgroups suggesting that at 30 years of age the mesothelioma risk is still increased substantially by continuing asbestos exposure The future burden of mesothelioma is thus still uncertain The death rate in men born around 1945 is higher up to 55 years of age than in any earlier or later birth cohort but few had substantial asbestos exposure after 30 years of age and we still do not know how rapidly their mortality will increase at older ages Contribution of amosite The mesothelioma risk caused by amosite brown asbestos is two orders of magnitude greater than that by chrysotile white asbestos Hodgson and Darnton 2000 and it seems likely that a major cause of the extraordinary risk to British carpenters was cutting amosite board with power tools which was widespread in the UK construction industry through the 1970s and continued into the 1980s A comparison of current mesothelioma death rates and imports to the US Virta 2006 and UK MRC Institute for Environment and Health 1997 of white brown and blue crocidolite asbestos also suggests that the much higher mesothelioma death in the UK was caused by its much greater use of amosite The mesothelioma death in men aged 45-49 is now more than three times higher in the UK than in deaths the US US 0.26 per 000 in 2000-2004 based on 139 UK 0.87 per 000 in 2001-2004 based on 66 deaths These men were born between 1950 and 1959 and few would have had much asbestos exposure before 1970. The UK used slightly less chrysotile during the 1970s 2.4 per head in 1970 1.7 in 1980 than the US 3.1 kg per head in 1970 1.5 in 1980 and the UK had virtually ceased using crocidolite by 1970 while US crocidolite imports increased from 8900 tonnes in 1970 to a peak of 900 tonnes 0.08 per head in 1978 and remained above 5000 tonnes per year until 1984. However the UK imported far more amosite per head than the US in the 1970s UK amosite imports were 600 tonnes 0.4 kg per head in 1970 and did not decline until after 1976 while US amosite imports fell from kg 12900 tonnes 0.07 per head in 1970 to 1400 tonnes in 1976 MRC Institute for Environment and Health 1997 Virta 2006 Australia's mesothelioma death are similar to Britain's and so were its patterns of amosite and crocidolite use Leigh and Driscoll 2003 The UK control limit remained the same for amosite as for chrysotile BOHS 1973 until 1983 when it was reduced from 2 to 1 fml for chrysotile and from 2 to fml 1 for amosite The fml control limit was probably observed in most asbestos factories during the 1970s and only four of the 512 male mesothelioma cases in our study had worked for more than 5 years in asbestos product manufacturing but substantial asbestos exposure was widespread in the much larger workforce in construction ACKNOWLEDGEMENTS We thank Maria Kelly for the majority of the telephone interviews and also Jayne Simpson Laura Newmark Bavithra Vijayakumar Chris Heaton Samantha Warnakulasuriya Qichen Liu Katie Field and Emma Afify for administrative work on the study Additional programming support was provided by Carl Gibbons and independent advice was obtained from Ben Armstrong Most importantly we thank the cases and controls who agreed to participate This research was supported by the Health & Safety Executive and Cancer Research UK REFERENCES Agudo A Gonzalez CA Bleda MJ Ramirez J Hernandez S Lopez F Calleja A Panades R Turuguet D Escolar A Beltran M Gonzalez JE case- 2000 Occupation and risk of malignant pleural mesothelioma a case- control study in Spain Am J Ind Med 37 159-168 Arblaster L Hatton P Howel D Renvoize E Schweiger M Swinburne LM 1995 Occupational and environmental links to mesothelioma deaths occurring in Leeds during 1987. J Public Health Med 17 297-304 297-304 297-304 Bard D Burdett G 2007 Exposure of UK Industrial Plumbers to Asbestos Part II awareness and responses of plumbers to working with asbestos during a survey in parallel with personal sampling Ann Occup Hyg 51 113-119 Berney LR Blane DB 1997 Collecting retrospective data accuracy of recall after 50 years judged against historical records Soc Sci Med 45 1519-1525 BOHS 1973 Hygiene standards for airborne amosite asbestos dust BOHS Committee on Hygiene Standards Ann Occup Hyg 16 1 5 Bourdes V Boffetta P Pisani P 2000 Environmental exposure to asbestos and risk of pleural mesothelioma review and analysis Eur J Epidemiol 16 411-417 Darnton AJ McElvenny DM Hodgson JT 2006 Estimating the number of asbestos lung cancer deaths in Great Britain from 1980 to 2000 Ann Occup Hyg 50 29-38 Goldberg M Imbernon E Rolland P Gilg Soit Ilg A Saves M de Quillacq A Frenay C Chamming's S Arveux P Boutin C Launoy G Pairon JC Astoul P Galateau F Brochard P 2006 The French National Mesothelioma Surveillance Program Occup Environ Med 63 3930 95 factory Hammond EC Garfinkel L Selikoff IJ Nicholson WJ experience of residents in the neighborhood of an Ann NY Acad Sci 330 417-422 417-422 417-422 1979 Mortality asbestos British Journal of Cancer 2009 100 1175-1183 HMSO 1965 The Building Regulations SI 1965 No. 1373 HMSO London Hodgson JT Darnton A 2000 The quantitative risks of mesothelioma and lung cancer in relation to asbestos exposure Ann Occup Hyg 44 565-601 565-601 565-601 Hodgson JT McElvenny DM Darnton AJ Price MJ Peto J 2005 The expected burden of mesothelioma mortality in Great Britain from 2002 to 2050. Br J Cancer 92 587-593 Holmes E Garshick E 1991 The reproducibility of the report of occupational exposure to asbestos and dust J Occup Med 33 134-138 Howel D Arblaster L Swinburne L Schweiger M Renvoize E Hatton P 1997 Routes of asbestos exposure and the development of mesothelioma in an English region Occup Environ Med 54 403-409 Iwatsubo Y Pairon JC Boutin C Menard O Massin N Caillaud D Orlowski E Galateau F Bignon J Brochard P 1998 Pleural mesothelioma dose-dose13-142 response relation at low levels of asbestos exposure in a French population- based control study Am J Epidemiol 148 133-142 133-142 Joubert L Seidman H Selikoff IJ 1991 Mortality experience of family contacts of asbestos factory workers Ann NY NY Acad Sci 643 416-418 Leigh J Driscoll T 2003 Malignant mesothelioma in Australia 1945-2002 Int J Occup Environ Health 9 206-217 Magnani C Dalmasso P Biggeri A Ivaldi C Mirabelli D Terracini B 2001 Increased risk of malignant mesothelioma of the pleura after residential or domestic exposure to asbestos a control study in Casale Monferrato Italy Environ Health Perspect 109 915-919 McElvenny DM Darnton AJ Price MJ Hodgson JT 2005 Mesothelioma mortality in Great Britain from 1968 to 2001. Occup Med Lond 55 79-87 MRC Institute for Environment and Health 1997 Fibrous materials in the environment a review of asbestos and made mineral fibres Leicester 1997 Muscat JE Wynder EL 1991 Cigarette smoking asbestos exposure and malignant mesothelioma Cancer Res 51 263-267 2263-2222636-22767 '2009 Cancer Research UK Newhouse ML Thompson H 1965 Mesothelioma of pleura and peritoneum following exposure to asbestos in the London area Br J Ind Med 22 261-269 261-269 Pan XL Day HW Wang W Beckett LA Schenker MB 2005 Residential proximity to naturally occurring asbestos and mesothelioma risk in California Am J Respir Crit Care Med 172 1019-1025 1019-1025 Rodelsperger K Jockel KH Pohlabeln H Romer W Woitowitz HJ 2001 Asbestos and made vitreous fibers as risk factors for diffuse case- malignant mesothelioma results from a German hospital case- control study Am J Ind Med 39 262-275 StataCorp 2007 Stata Statistical Software Release 9.2 Stata Corporation College Station Texas UK mesothelioma control study C Rake et al mpg 1183 Teschke K Morgan MS Checkoway H Franklin G Spinelli JJ van Belle G Weiss NS 1997 Mesothelioma surveillance to locate sources of exposure to asbestos Can J Public Health 88 163-168 Vianna NJ Polan AK 1978 occupational exposure to asbestos and malignant mesothelioma in females Lancet 1 1061 - 1063 Virta RL 2006 Worldwide asbestos supply and consumption trends from 1900 through 2003. US Geological Survey Circular 1298. Accessed June 19th 2008 at http://pubs.usgs.gov/circ/2006/1298 Yeung P Rogers A Johnson A 1999 Distribution of mesothelioma cases in different occupational groups and industries in Australia 1979-1995 Appl Occup Environ Hyg 14 759-767 '2009 Cancer Research UK British Journal of Cancer 2009 100 1175-1183