title: Childhood leukaemia and distance from power lines in California: a population-based case-control study.
abstract: Studies have reported an increased risk of childhood leukaemia associated with living near high-voltage electric power transmission lines that extend to distances at which magnetic fields from lines are negligible. We conducted a large records-based case-control study of childhood leukaemia risk in the population living near power lines in California.
  
  
  
  The study included 5788 childhood leukaemia and 3308 central nervous system (CNS) cancer cases (for comparison) born in and diagnosed in California (1986-2008), and matched to population-based controls by age and sex. We geocoded birth address and estimated the distance from residence to transmission lines using geographic information systems, aerial imagery, and, for some residences, site visits.
  
  
  
  For leukaemia, there was a slight excess of cases within 50 m of a transmission line over 200 kV (odds ratio 1.4, 95% confidence interval 0.7-2.7). There was no evidence of increased risk for distances beyond 50 m, for lower-voltage lines, or for CNS cancers.
  
  
  
  Our findings did not clearly support an increased childhood leukaemia risk associated with close proximity (<50 m) to higher voltage lines, but could be consistent with a small increased risk. Reports of increased risk for distances beyond 50 m were not replicated.
authors.affiliation: Department of Biostatistics, University of California Los Angeles Fielding School of Public Health, 650 Charles E. Young Drive South, Los Angeles, CA 90095-1772, USA.
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Crespi
authors.affiliation: Environment Sector, Electric Power Research Institute, Palo Alto, CA 94304, USA.
authors.forename: Ximena P
authors.initials: XP
authors.lastname: Vergara
authors.affiliation: Enertech Consultants, Campbell, CA 95008, USA.
authors.forename: Chris
authors.initials: C
authors.lastname: Hooper
authors.affiliation: Department of Epidemiology, UCLA Fielding School of Public Health, University of California Los Angeles, Los Angeles, CA 90095-1772, USA.
authors.forename: Sona
authors.initials: S
authors.lastname: Oksuzyan
authors.affiliation: Department of Biostatistics, University of California Los Angeles Fielding School of Public Health, 650 Charles E. Young Drive South, Los Angeles, CA 90095-1772, USA.
authors.forename: Sheng
authors.initials: S
authors.lastname: Wu
authors.affiliation: Department of Preventive Medicine, University of Southern California, Los Angeles, CA 90032, USA.
authors.forename: Myles
authors.initials: M
authors.lastname: Cockburn
authors.affiliation: Department of Epidemiology, UCLA Fielding School of Public Health, University of California Los Angeles, Los Angeles, CA 90095-1772, USA.
authors.forename: Leeka
authors.initials: L
authors.lastname: Kheifets
mesh_terms: D000293:Adolescent; D002140:California; D016022:Case-Control Studies; D016543:Central Nervous System Neoplasms / Q000209:etiology; D002648:Child; D002675:Child, Preschool; D004560:Electricity / Q000009:adverse effects*; D004574:Electromagnetic Fields / Q000009:adverse effects*; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007223:Infant; D007938:Leukemia / Q000209:etiology*; D060526:Magnetic Fields / Q000009:adverse effects*; D008297:Male; D012306:Risk