Proximity to overhead power lines and childhood leukaemia: an international pooled analysis

Aryana T Amoon, Catherine M Crespi, Anders Ahlbom, Megha Bhatnagar, Isabelle Bray, Kathryn J Bunch, Jacqueline Clavel, Maria Feychting, Denis Hémon, Christoffer Johansen, Christian Kreis, Carlotta Malagoli, Fabienne Marquant, Camilla Pedersen, Ole Raaschou-Nielsen, Martin Röösli, Ben D Spycher, Madhuri Sudan, John Swanson, Andrea Tittarelli, Deirdre M Tuck, Tore Tynes, Ximena Vergara, Marco Vinceti, Victor Wünsch-Filho, Leeka Kheifets

Although studies have consistently found an association between childhood leukaemia risk and magnetic fields, the associations between childhood leukaemia and distance to overhead power lines have been inconsistent. We pooled data from multiple studies to assess the association with distance and evaluate whether it is due to magnetic fields or other factors associated with distance from lines. We present a pooled analysis combining individual-level data (29,049 cases and 68,231 controls) from 11 record-based studies. There was no material association between childhood leukaemia and distance to nearest overhead power line of any voltage. Among children living < 50 m from 200 + kV power lines, the adjusted odds ratio for childhood leukaemia was 1.33 (95% CI: 0.92-1.93). The odds ratio was higher among children diagnosed before age 5 years. There was no association with calculated magnetic fields. Odds ratios remained unchanged with adjustment for potential confounders. In this first comprehensive pooled analysis of childhood leukaemia and distance to power lines, we found a small and imprecise risk for residences < 50 m of 200 + kV lines that was not explained by high magnetic fields. Reasons for the increased risk, found in this and many other studies, remains to be elucidated.