title: A case-control study of occupational exposure to metalworking fluids and bladder cancer risk among men.
abstract: OBJECTIVE
  Metalworking has been associated with an excess risk of bladder cancer in over 20 studies. Metalworking fluids (MWFs) are suspected as the responsible exposure, but epidemiological data are limited. We investigated this association among men in the New England Bladder Cancer Study using state-of-the-art, quantitative exposure assessment methods.
  
  
  METHODS
  Cases (n=895) and population controls (n=1031) provided occupational histories during personal interviews. For selected jobs, exposure-oriented modules were administered to collect information on use of three MWF types: (1) straight (mineral oil, additives), (2) soluble (mineral oil, water, additives) and (3) synthetic (water, organics, additives) or semisynthetic (hybrid of soluble and synthetic). We computed ORs and 95% CIs relating bladder cancer risk to a variety of exposure metrics, adjusting for smoking and other factors. Non-metalworkers who had held jobs with possible exposure to mineral oil were analysed separately.
  
  
  RESULTS
  Bladder cancer risk was elevated among men who reported using straight MWFs (OR=1.7, 95% CI 1.1 to 2.8); risk increased monotonically with increasing cumulative exposure (p=0.041). Use of soluble MWFs was associated with a 50% increased risk (95% CI 0.96 to 2.5). ORs were non-significantly elevated for synthetic/semisynthetic MWFs based on a small number of exposed men. Non-metalworkers holding jobs with possible exposure to mineral oil had a 40% increased risk (95% CI 1.1 to 1.8).
  
  
  CONCLUSIONS
  Exposure to straight MWFs was associated with a significantly increased bladder cancer risk, as was employment in non-metalworking jobs with possible exposure to mineral oil. These findings strengthen prior evidence for mineral oil as a bladder carcinogen.
authors.affiliation: Department of Health and Human Services, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Joanne S
authors.initials: JS
authors.lastname: Colt
authors.affiliation: Department of Health and Human Services, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Melissa C
authors.initials: MC
authors.lastname: Friesen
authors.affiliation: Department of Health and Human Services, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA Stewart Exposure Assessments, LLC, Arlington, Virginia, USA.
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Stewart
authors.affiliation: Korea National Open University, Seoul, Korea.
authors.forename: Park
authors.initials: P
authors.lastname: Donguk
authors.affiliation: Vermont Cancer Registry, Burlington, Vermont, USA.
authors.forename: Alison
authors.initials: A
authors.lastname: Johnson
authors.affiliation: Maine Cancer Registry, Augusta, Maine, USA.
authors.forename: Molly
authors.initials: M
authors.lastname: Schwenn
authors.affiliation: Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA.
authors.forename: Margaret R
authors.initials: MR
authors.lastname: Karagas
authors.affiliation: New Hampshire Department of Health and Human Services, Concord, New Hampshire, USA.
authors.forename: Karla
authors.initials: K
authors.lastname: Armenti
authors.affiliation: Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA.
authors.forename: Richard
authors.initials: R
authors.lastname: Waddell
authors.affiliation: Maine Cancer Registry, Augusta, Maine, USA.
authors.forename: Castine
authors.initials: C
authors.lastname: Verrill
authors.affiliation: Department of Health and Human Services, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Mary H
authors.initials: MH
authors.lastname: Ward
authors.affiliation: Department of Health and Human Services, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Laura E Beane
authors.initials: LE
authors.lastname: Freeman
authors.affiliation: Department of Health and Human Services, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Lee E
authors.initials: LE
authors.lastname: Moore
authors.affiliation: Department of Health and Human Services, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Stella
authors.initials: S
authors.lastname: Koutros
authors.affiliation: Department of Health and Human Services, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Dalsu
authors.initials: D
authors.lastname: Baris
authors.affiliation: Department of Health and Human Services, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Debra T
authors.initials: DT
authors.lastname: Silverman
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D006801:Humans; D008297:Male; D008669:Metallurgy; D008875:Middle Aged; D009511:New England / Q000453:epidemiology; D016273:Occupational Exposure; D012307:Risk Factors; D001749:Urinary Bladder Neoplasms / Q000453:epidemiology*