Child Leukemia Again Linked to Power Lines
Study: Slight Tendency for Kids With Leukemia to Live Near Power Lines
June 2, 2005 -- Living near high-voltage power lines raises children's risk of leukemia by 69%, a British study shows.
That doesn't prove that power lines cause the deadly blood cancer, the study's authors are quick to point out. Despite 30 years of research, scientists still can't come up with a plausible reason why the weak magnetic fields near power lines might cause leukemia.
Gerald Draper, DPhil, director of the childhood cancer research group at Oxford University, led the study. Draper's team compared more than 29,000 children with cancer, including 9,700 children with leukemia, to age-, sex-, and birthplace-matched children without cancer. The children's birth homes were located on the power grids of England and Wales.
Compared with children who lived more than 600 meters from a high-voltage power line, those who lived within 200 meters of the power lines had a 69% greater risk of leukemia. Those living 200 to 600 meters from power lines had a 23% higher risk of leukemia. The findings appear in the June 4 issue of the British Medical Journal.
There is a slight tendency for the birth addresses of children with leukemia to be closer to these lines than those of children matched for comparison, Draper and colleagues write. "We have no satisfactory explanation for our results in terms of causation by magnetic fields, and the findings are not supported by convincing laboratory data or any accepted biological mechanism."
An Unusual Disclaimer
That's an unusual disclaimer for a researcher who has found a statistically significant link. But the data leave Draper and other experts scratching their heads for an explanation.
There are many theories about how power lines might cause leukemia. The most obvious one is that the magnetic fields created by power lines somehow make cancer cells grow in susceptible people. But there's a problem with this theory, notes Heather Dickinson, PhD, principal research associate at the Center for Health Services Research at the University of Newcastle in England.
"What is puzzling is that the magnetic field from power lines is only 1% of the earth's magnetic field, which surrounds us all," Dickinson tells WebMD. "Your fridge or vacuum generates a magnetic field of about the same strength. In England and Wales, only 5% of the exposure to magnetic fields comes from high voltage pylons. So if this is a hazard, people with appliances should be just as concerned."