Tittarelli ACancer Registry Unit, National Cancer Institute, Milan, 20133, Italy.
Tuck DMSchool of Medicine, University of Tasmania, Hobart, TAS, Australia.
Tynes TDepartment of Occupational Health Surveillance, National Institute of Occupational Health, Oslo, Norway.
Vergara XDepartment of Epidemiology, University of California Los Angeles Fielding School of Public Health, Los Angeles, CA, 90095-1772, USA.
Vinceti MResearch Center of Environmental (CREAGEN), Genetic and Nutritional Epidemiology University of Modena and Reggio Emilia, Modena, Italy.
Wünsch-Filho VDepartment of Epidemiology, School of Public Health, University of São Paulo, São Paulo, 01246-904, Brazil.
Kheifets LDepartment of Epidemiology, University of California Los Angeles Fielding School of Public Health, Los Angeles, CA, 90095-1772, USA. kheifets@ucla.edu.
English
BACKGROUND 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.
METHODS We present a pooled analysis combining individual-level data (29,049 cases and 68,231 controls) from 11 record-based studies.
RESULTS 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.
CONCLUSIONS 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.