Bladder cancer and occupational exposure to diesel and gasoline engine emissions among Canadian men

Lidija LATIFOVIC, Cancer Care Ontario, Canada
PARENT M. 4 , VILLENEUVE P. 2,3,7 , HARRIS S. 1,3,6,7 , KACHURI L. 1,3,6 , JOHNSON K. 5

1 Prevention and Cancer Control, Cancer Care Ontario, Toronto, Ontario, Canada
2 CHAIM Research Centre, Carleton University, Ottawa, Ontario, Canada
3 Occupational Cancer Research Center, Toronto, Ontario, Canada
4 INRS-Institut Armand-Frappier, Institut national de la recherche scientifique, University of Quebec, Laval, Quebec, Canada
5 School of Epidemiology, Public Health and Preventive Medicine, University of Ottawa, Ottawa, Ontario, Canada
6 Division of Epidemiology, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
7 Division of Occupational and Environmental Health, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada

Purpose: IARC has classified diesel engine emissions (DEE) as a carcinogen and gasoline engine emissions (GEE) as a possible carcinogen based on evidence for lung cancer. The purpose of this study was to investigate the effect of exposure to DEE and GEE on bladder cancer in occupationally exposed men using data from the Canadian National Enhanced Cancer Surveillance System.
 
Methods: This analysis included 658 cases and 1360 controls recruited from seven Canadian provinces (1994-97). Lifetime occupational history, including job title, status and duties, and information on possible cancer risk factors was obtained by self-reported questionnaire. Concentration and frequency of occupational exposure to DEE and GEE, and a measure of the reliability of exposure assessment, was assigned for each job using a job-exposure matrix supplemented by expert review. Exposure metrics were modeled as ever-never, highest attained concentration, highest attained frequency, duration, and cumulative exposure. Logistic regression was used to calculate adjusted odds ratios and 95% confidence intervals.
 
Results: Relative to unexposed, men ever exposed to high concentrations of DEE were at an increased risk of bladder cancer (OR=1.64, 95%CI=0.87–3.08), and those with >10 years of exposure to DEE at high concentrations had a greater than twofold increase in risk (OR=2.45, 95%CI=1.04–5.74). Increased risk of bladder cancer was also observed with >30% of work time exposed to GEE (OR = 1.59, 1.04–2.43) relative to the unexposed, but only among men that had never been exposed to diesel engine emissions.
 
Conclusions: Our results suggest that occupational exposure to high concentrations of diesel engine emissions may increase the risk of bladder cancer.
 
Funding source: This research was funded by the Workplace Safety and Insurance Board (Ontario), WSIB#10011, with support from the Ontario Occupational Cancer Research Center and Health Canada. MÉ Parent received funds from Fonds de recherche du Québec-Santé (FRQS).