Overhead electricity power lines and childhood leukemia: A registry-based, case-control study

Aims and background: To evaluate the role of exposure to low-frequency electromagnetic fields generated by overhead power lines on the risk of childhood leukemia, we carried out a case-control study in the area (Varese province) covered by the Lombardy Cancer Registry. Methods and study design: Exposure to magnetic fields was estimated using line load data and the distance between subjects' homes and the nearest power line. A total of 101 cases and 412 controls were investigated. Results: Twenty subjects (9 cases and 11 controls) were considered exposed. A significant fourfold increase in risk for leukemia in exposed subjects and a dose-response relationship were found. The risk was higher than that reported by other studies. Potential biases related to the representativity of controls and validity of exposure assessment do not seem to have influenced the risk estimates. Conclusions: We suggest that measures to remedy residential exposure should be taken wherever practicable.