Occupational risk factors, ultraviolet radiation, and ocular melanoma: a case-control study in France

Background: Ultraviolet radiation has been suspected as a possible cause of ocular melanoma. Because this association is controversial, we examine the role of occupational exposure to ultraviolet radiation on the occurrence o f this rare cancer. Material and methods: A population-based case-control study was conducted i n 10 French administrative areas (departements). Cases were 50 patients wit h uveal melanoma diagnosed in 1995-1996. Controls were selected at random f rom electoral rolls, after stratification for age, gender, and area. Among 630 selected persons, 479 (76%) were interviewed. Data on personal characte ristics, occupational history, and detailed information on each job held we re obtained from face-to-face interviews using a standardized questionnaire . Estimates of occupational exposure to solar and artificial ultraviolet li ght were made using a job exposure matrix. Results: Results show elevated risks of ocular melanoma for people with lig ht eye color, light skin color, and for subjects with several eye burns. Th e analysis based on the job exposure matrix showed a significantly increase d risk of ocular melanoma in occupational groups exposed to artificial ultr aviolet radiation, but not in outdoor occupational groups exposed to sunlig ht. An elevated risk of ocular melanoma was seen among welders (odds ratio = 7.3; 95% confidence interval = 2.6-20.1 for men), and a dose-response rel ationship with job duration was observed. The study also showed increased r isk of ocular melanoma among male cooks, and among female metal workers and material handling operators. Conclusion: Following the present study, the existence of an excess risk of ocular melanoma in welders may now be considered as established. Exposure to ultraviolet light is a likely causal agent, but a possible role of other exposures in the welding processes should not be overlooked.