Background Diesel motor exhaust is a recognised risk factor for lung cancer, but few studies have investigated the effect of diesel emissions on other parts of the respiratory tract. We used data from the ICARE study, a French population-based case-control study, to investigate the associations between exposure to diesel motor exhaust and the risk of cancer of the oral cavity, pharynx and larynx.

Methods The analysis was restricted to men and included cases of squamous cell carcinomas of the oral cavity, oropharynx, hypopharynx and larynx (350, 543, 383 and 454 cases, respectively) and 2780 controls. Detailed information on lifetime occupational history, tobacco smoking and alcohol drinking was collected by interview. We assessed occupational exposure to diesel motor exhaust from questionnaire responses. We used logistic regression to estimate odds ratios (OR) and their 95% confidence intervals (CI), adjusted for age, residence area, smoking, alcohol drinking and asbestos exposure.

Results No association was found between exposure to diesel motor exhaust and cancer of the oral cavity (OR=0.88, CI=0.65–1.18), oropharynx (OR=0.83, CI=0.65–1.10), hypopharynx (OR=0.84, CI=0.65–1.18) or larynx (OR=1.11, CI=0.86–1.43). There was no indication of increasing risk with increasing duration of exposure, for any of the cancer sites.

Conclusion These findings do not provide evidence that occupational exposure to diesel motor exhaust increases the risk of oral, pharyngeal or laryngeal cancer.