Occupational exposure to electromagnetic fields and Alzheimer disease

The association between occupational exposure to electromagnetic fields (EM F) and Alzheimer disease (AD) was examined. Subjects were identified from a large health maintenance organization in Seattle, Washington, and matched by age, sex, and proxy type. A complete occupational history was obtained f rom proxies and controls. Following the interview, two industrial hygienist s (Ms) rated exposures to EMF for each job blinded to case-control status. Exposures to EMF were rated as probable intermittent exposure or probable e xposure for extended periods to levels above threshold. Conditional logisti c regression was used to calculate the risk of AD given EMF exposure strati fied by IH. The odds ratios for ever having been exposed to EMF were 0.74 [ 95% confidence interval (CI) 0.29-1.92] and 0.95 (95% CI 0.27-2.43) for eac h IH, adjusting for age and education. No dose-response effect was noted. A greement between the two IHs for ever having been exposed to EMF was good ( kappa = 0.57, p < 0.0001). This study was unable to support an association between EMF and AD.