Combined risk estimates for two German population-based case-control studies on residential magnetic fields and childhood acute leukemia

From 1992 to 1996, we obtained electromagnetic field measurements in two population-based case-control studies on childhood leukemia in the northwestern part of Germany and in Berlin. Exposure assessment comprised residential 24-hour measurements and short-term measurements. We obtained 24hour measurements for a total of 176 cases and 414 controls. We compared subjects exposed to median 24-hour measureme ts of 0.2 uT or more with those exposed to lower amounts. Multivariate regression analysis revealed an odds ratio of 2.3 (95% confidence interval = 0.8-6.7). (Epidemiology 1997;9: 92 94)