Quantitative exposure to metalworking fluids and bladder cancer incidence in a cohort of autoworkers.
Occupations with mineral oil exposure have been associated with bladder cancer in population-based case-control studies. The authors report results from the first cohort study to examine bladder cancer incidence in relation to quantitative exposures to metalworking fluids (MWFs), based on 21,999 male Michigan automotive workers, followed from 1985 through 2004. Cox regression was used to estimate hazard ratios based on categorical exposure variables for straight, soluble, and synthetic MWFs, as well as duration of exposure to ethanolamines and nitrosamines. Penalized splines were also fit to estimate the functional form of the exposure-response relation. Increased bladder cancer risk was associated with straight MWFs but not with any other exposure. The hazard ratio increased with cumulative exposure to a maximum of 2-fold observed at 75 mg/m(3)-year straight MWF exposure (lagged 20 years). Calendar time windows relevant to polycyclic aromatic hydrocarbon exposure were examined but could not be distinguished from the lagged (10-, 20-year) metrics. No association was observed between any exposure and incident lung cancer, suggesting that smoking is unlikely to confound the associations observed here. The quantitative relation with straight MWFs strengthens the evidence for mineral oils as a bladder carcinogen.
Friesen
Melissa C
MC
Environmental Health Sciences Division, School of Public Health, University of California, Berkeley, California 94720-7360, USA.
Costello
Sadie
S
Eisen
Ellen A
EA
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001336:Automobiles; D015331:Cohort Studies; D004983:Ethanolamines / Q000633:toxicity*; D006801:Humans; D015994:Incidence; D007221:Industry; D008175:Lung Neoplasms / Q000139:chemically induced / Q000453:epidemiology / Q000209:etiology; D008297:Male; D008670:Metals / Q000633:toxicity; D008875:Middle Aged; D009602:Nitrosamines / Q000633:toxicity*; D016273:Occupational Exposure / Q000009:adverse effects*; D016272:Occupational Health / Q000706:statistics & numerical data; D011084:Polycyclic Aromatic Hydrocarbons / Q000633:toxicity; D016016:Proportional Hazards Models; D012044:Regression Analysis; D012189:Retrospective Studies; D012306:Risk; D012307:Risk Factors; D014481:United States / Q000453:epidemiology; D001749:Urinary Bladder Neoplasms / Q000139:chemically induced / Q000453:epidemiology* / Q000209:etiology
D004983:Ethanolamines; D008670:Metals; D009602:Nitrosamines; D011084:Polycyclic Aromatic Hydrocarbons