AUTHORS: R. Lovely et al.
American Journal of Epidemiology. 1994:140(6) p. 510-517.
STUDY DESIGN: Interview data from a 1981 registry- based case control study was used to test the hypothesis that the use of personal electric appliances was associated with a greater risk of acute nonlymphocytic leukemia (ANLL). The 114 cases were obtained from the western Washington State cancer registry. Controls were obtained through random digit dialing in the same geographic area and matched for age and sex. Exposure assessment was obtained through a questionnaire. As many cases were deceased, information was often obtained from next of kin. Researchers concentrated on appliance use data for electric razors, hair dryers, and massage units as they are all motor driven and are used close to the body. Because magnetic fields for small electric appliances drop off quickly with distance, proximity to the body is an important consideration.
CONCLUSION: No association was observed between appliance use and increased risk of acute nonlymphocytic leukemia when categorizing appliance use by ever used/never used of one or more of the appliances (OR=0.71, 95% CI=0.41- 1.24). A statistically significant association was observed with respect to use of massage units and ANLL (OR=3.00, 95% CI 1.43-6.32); massage units were three times as likely to be used by cases than by controls. There was no evidence of a dose-response relationship dependent on duration of daily use for any of the appliances investigated.
LIMITATIONS: Inferences that can be drawn from this study are limited. Proxy reporting for deceased cases for duration of use can be unreliable. Additionally the small number of cases included in the study limits the ability of the study to detect an association. However this study was designed to be preliminary and the authors believe that further investigation of personal appliance use and its potential association with acute nonlymphocytic leukemia is warranted.