Exposure to overhead high-voltage power lines and childhood leukemia risk: an Italian population-based case-control study

Background Previous epidemiologic findings suggest a positive association between magnetic field exposure induced by high voltage power lines and childhood leukemia (CL). Contrasting results are still reported, possibly biased by exposure misclassification, relying on different assessment methods across studies, and by unmeasured confounders. Methods/Approach We further studied this relation in the Modena and Reggio Emilia provinces (Northern Italy), and through a modelling exposure assessment we identified the corridors along high voltage power lines with magnetic field intensity in the 0.1-0.4 µT ranges. Then we identified 182 cases of newly-diagnosed CL within these provinces from 1998 to 2019. We sampled four age-, sex-, province of residence- and calendar year- matched controls for each case. We computed the odds ratio (OR) and its 95% confidence interval (CI) of CL in a conditional logistic regression analysis according to distance between home address at the time of diagnosis of the case and the nearest high voltage power line and also to residential magnetic field modeled intensity. Results OR of CL was 0.9 (95% CI 0.5-1.6), 0.9 (95% CI 0.4-2.0), 1.5 (95% CI 0.5-4.7) and 4.0 (95% CI 1.0-16.0) for children living respectively 200-400 m, 100-200 m, 50-100 m, and less than 50 m from the nearest high voltage power line compared to those residing further than 400 m. OR of CL associated with residence in the area with exposure >0.1 µT was 8.0 (95% CI 0.7-88.2). Conclusions Though the number of exposed children in this study was too low to allow firm conclusions, yielding in such cases high but very imprecise estimates, our results seem more suggestive of an excess risk of leukemia among children living close to electric power lines or exposed to higher magnetic fields intensity.