Childhood cancer and magnetic fields from high-voltage power lines in England and Wales: a case-control study.
BACKGROUND
Epidemiological evidence suggests that chronic low-intensity extremely-low-frequency magnetic-field exposure is associated with increased risk of childhood leukaemia; it is not certain the association is causal.


METHODS
We report a national case-control study relating childhood cancer risk to the average magnetic field from high-voltage overhead power lines at the child's home address at birth during the year of birth, estimated using National Grid records. From the National Registry of Childhood Tumours, we obtained records of 28,968 children born in England and Wales during 1962-1995 and diagnosed in Britain under age 15. We selected controls from birth registers, matching individually by sex, period of birth, and birth registration district. No participation by cases or controls was required.


RESULTS
The estimated relative risk for each 0.2 μT increase in magnetic field was 1.14 (95% confidence interval 0.57 to 2.32) for leukaemia, 0.80 (0.43-1.51) for CNS/brain tumours, and 1.34 (0.84-2.15) for other cancers.


CONCLUSIONS
Although not statistically significant, the estimate for childhood leukaemia resembles results of comparable studies. Assuming causality, the estimated attributable risk is below one case per year. Magnetic-field exposure during the year of birth is unlikely to be the whole cause of the association with distance from overhead power lines that we previously reported.
Kroll
M E
ME
University of Oxford, Childhood Cancer Research Group, Richards Building, Old Road Campus, Headington, Oxford OX3 7LG, UK. mary.kroll@ccrg.ox.ac.uk
Swanson
J
J
Vincent
T J
TJ
Draper
G J
GJ
D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004574:Electromagnetic Fields / Q000009:adverse effects*; D004739:England; D004781:Environmental Exposure / Q000009:adverse effects; D006801:Humans; D007953:Leukemia, Radiation-Induced / Q000453:epidemiology; D009369:Neoplasms / Q000453:epidemiology* / Q000209:etiology; D009381:Neoplasms, Radiation-Induced / Q000453:epidemiology; D012306:Risk; D014852:Wales