Electromagnetic Fields and Childhood Leukemia: Pooled Analyses of Two German Population-Based Case-Control Studies

From 1992 to 1995 we conducted a population-based case-control study on residential magnetic fields and childhood leukemia in Lower Saxony, a region in northwestern Germany with 7.4 million inhabitants.1,2 Because of the rural character of this area, we detected elevated magnetic fields in only 1.5% of all dwellings. We therefore expanded the EMF-measurements to an ongoing case-control study on childhood leukemia in the capital of Germany, Berlin. We applied the same methods of exposure assessment, intending to pool the data of the two studies and to calculate combined risk estimates.3