Invited commentary: are low radiation doses or occupational exposures really risk factors for malignant melanoma?

Concerns about a possible association between melanoma and employment in the nuclear industry first surfaced in the early 1980s (1), and even earlier with regard to employment in other industries (2). Although occupationally related skin disorders were first observed in the 1700s (3), and although radiationinduced skin erythemas and skin cancers were observed among early radiation workers as well as among populations undergoing radiation therapy (4, 5), observations regarding the possible association between occupational exposures and melanoma have tended to receive little credence (6). In 1981, Austin et al. (1) reported results from a retrospective cohort study, including a fourfold increase in the incidence of melanoma, among workers at the Lawrence Livermore National Laboratory (LLNL) in Livermore, California. These findings generated concern that other nuclear workers might be similarly subject to increased risk of melanoma, perhaps due to job-related exposures to low doses of ionizing radiation. Studies carried out at a sister laboratory, Los Alamos National Laboratory (LANL) (7, 8), indicated that increased melanoma incidence did not exist among LANL workers as a whole (7), and further that only increasing education level was clearly associated with the occurrence of incident melanoma within this cohort (8). The case-control study reported by Austin and Reynolds (9) in this issue of the Journal continues the analysis of melanoma among LLNL workers that was originally reported in 1981 (1). The current investigation expands the total number of melanoma cases from the 19 reported in the 1981 study to 31. The study window for case ascertainment is also increased from