Background The risk factors for sporadic (ie, non-familial) retinoblastoma remain largely unknown.

Objectives We examined the relationship between paternal occupational exposures from jobs held 10 years and 1 year prior to conception and the risk of sporadic bilateral retinoblastoma in children.

Methods Paternal occupational data were obtained for 198 incident cases diagnosed with sporadic bilateral retinoblastoma from January 1998 to May 2006 and 245 referral-based controls from the case child's relatives and friends who were matched to 135 of the cases on birth year. Industrial hygienists independently assigned exposure scores for nine agents. Adjusted ORs and 95% CIs were computed using logistic regression models, using the full sample of cases and controls as well as subset of cases with matched controls only.

Results There was some indication of an elevated risk associated with paternal pesticide exposure in the 10 years prior to conception (OR=1.64; 95% CI 1.08 to 2.50) as well as in the year before conception (OR=2.12; 95% CI 1.25 to 3.61). However, results for pesticide exposure were inconsistent and varied by analysis approach. An increased risk was also observed for non-welding metal exposure during the 10 years prior to conception in the full (OR=1.35; 95% CI 0.86 to 2.12) and matched (OR=1.40; 95% CI 0.82 to 2.37) samples, but not in the year before conception. Exposure–response trends were observed for pesticides and non-welding metal exposures.

Conclusions Our findings suggest a potential role of paternal occupational exposures to non-welding metals and perhaps pesticides in the aetiology of childhood retinoblastoma.