Objectives We aimed to evaluate the risks of lung cancer associated with exposure to benzene, to toluene and to xylene.

Method Two population-based case-control studies conducted in Montreal included 1896 lung cancer cases and 1908 controls. Study I was conducted in 1980–1986, and study II in 1995–2001. Occupational exposures were assessed using a combination of subject-reported job history and expert assessment. Participants provided information on sociodemographic characteristics and smoking history. Using logistic regression, we evaluated the risk of lung cancer due to the exposure to each agent.

Results Lifetime exposure prevalence ranged from 12% for xylene to 20% for benzene in study I, and 11% for xylene to 15% for benzene in study II. In both studies, 25% of the participants were exposed to benzene, toluene or xylene. Pooling studies, the odds ratios and 95% confidence interval (OR) for ever-exposure to any of the evaluated agents was 1.2 (1.0–1.4). In analyses including all subjects but only one agent at a time in the models, ORs were around 1.2–1.3 for each agent. When we excluded subjects ever exposed to two or three of these agents, none of the agents showed excess risk. Being ever exposed to all three agents was associated with lung cancer (OR: 1.3; 1.0–1.6). Attempts to estimate ORs for each agent while controlling for the two others resulted in co-linearity.

Conclusions We found no clear indications of an association between lung cancer and exposure to toluene or xylene, but there was some evidence for an association with benzene.