Residential exposure to magnetic field due to high-voltage power lines and childhood leukemia risk in mainland France - GEOCAP case-control study, 2002-2010.

BACKGROUND

Environmental exposure to extremely low frequency magnetic fields (ELF-MF) is suspected of being a risk factor of childhood acute leukemia (AL) and classified as possible carcinogen. Results of recent epidemiological studies remain however heterogeneous.

OBJECTIVE

The present study aimed to evaluate AL risk in children exposed to ELF-MF by living close to high-voltage overhead power lines (HVOL) in France.

METHODS

We included 4117 AL cases under the age of 15 diagnosed in 2002-2010 and 44,838 contemporary controls representative of the French pediatric population, drawn from the national registry-based GEOCAP study. The distance between the geocoded address of residence and the closest 63-400 kV HVOL, and the closest 225-400 kV HVOL, were evaluated. ELF-MF exposure was also calculated at the geocoded addresses considering the characteristics of the neighboring HVOLs. Logistic regression models adjusted for age were used to estimate odds-ratios (OR) and 95 % confidence intervals. Sensitivity analyses were carried out to account for geocoding error and potential confounders.

RESULTS

0.7 % of the controls lived within 50 m of HVOL and 0.3 % were exposed to more than 0.3 μT. Living within 50 m of HVOL was associated with an increased risk of AL for children under 5 (OR = 1.6 (1.0-2.7)), an association more marked when restricting to the high-quality geocoded addresses (OR = 3.2 (1.3-7.9)). ELF-MF was not associated with AL risk (≥0.3 μT, OR = 0.6 (0.3-1.3)). The results remained stable in all the sensitivity analyses.

CONCLUSION

Our study brings new evidence that ELF-MF are probably not associated with AL risk, and cannot explain an association with distance to HVOL.