Use of electric blankets and risk of testicular cancer.

Electric blankets are an important domestic source of electromagnetic fields (EMF) because of the relatively high intensity of emission, prolonged exposure, and intimate contact with the source. In a case-control study of testicular cancer in western Washington during 1981 to 1984, the relation between EMF exposure from electric blankets and the occurrence of testicular cancer was examined. The respective proportions of cases and controls who reported the use of an electric blanket were almost identical (age-adjusted rate ratio (RR) = 1.0, 95% confidence interval (CI) 0.7-1.4). Distributions of the duration of use were also very similar in cases and controls. Compared with controls, the frequency of use of an electric blanket was slightly lower in men with seminoma (RR = 0.7, 95% CI 0.5-1.2) and slightly higher among men with nonseminoma germ cell tumors (RR = 1.4, 95% CI 0.9-2.3). Overall, the results of this study suggest that increased exposure to EMF from electric blankets contributes little, if at all, to the risk of testicular cancer in adult white men.