[Risk of cancer among Danish electricity workers. A cohort study]

We report the incidence of cancer in a large cohort of employees identified from all 99 Danish utility companies. Personal data, and information on employment and exposure to magnetic fields and asbestos were obtained from manual files at the companies, the Danish Supplementary Pension Fund and the public payroll administration. A total of 32,006 individuals with more than three months of employment were linked with the files of the Danish Cancer Registry. Overall, 3008 cancers were observed, with 2825 expected, yielding a small but significantly increased risk of 1.06 (95% CI, 1.03-1.10). No excess was observed for all leukemias or for cancers of the brain or breast among men or women. There was no association of electromagnetic field exposure with risk of these cancers even when the level and length of exposure to magnetic fields were taken into account. Increased risks for cancers of the lung and pleural cavity were seen mainly for workers whose jobs involve exposure to asbestos. Our results do not support the hypothesis of an association between occupational exposures to magnetic fields in the electric utility industry and the risk for cancer.