Electrical occupations and neurodegenerative disease: analysis of U.S. mortality data.

Investigators have hypothesized that occupations involving electric and magnetic field exposure are associated with a variety of health problems, including neurological disease. The authors conducted a case-control study, and they used U.S. death certificates with occupational coding to compare male cases of Alzheimer's disease (n = 256), Parkinson's disease (n = 168), and amyotrophic lateral sclerosis (n = 114) with controls matched for age and calendar time. The authors selected controls in a 3:1 ratio to cases from persons who died of causes other than leukemia, brain cancer, and breast cancer. Overall associations with electrical occupations were modest (i.e., adjusted odds ratios of 1.2, 1.1, and 1.3 for Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis, respectively). Individual electrical occupations were associated more strongly with disease than overall electrical occupations, particularly amyotrophic lateral sclerosis, for which relative risks ranged from 2 to 5 across several job categories. The largest associations with all three diseases occurred for power plant operators.