British medical researchers say their studies suggest that children who live in close proximity to high-voltage power cables at birth are much more likely to develop leukemia. The Oxford University scientists say they found that children who lived within approximately 200 feet of the power lines had a 70 percent higher chance of developing the disease than children who lived more than 600 feet away.

The researchers were quick to say that the results of their study could merely be coincidence, or that the cancer incidence among children might be related to other factors.

But their study found that when they measured the cancer rate among children who lived more than 200 feet from power cables but less than 600 feet, there was still an increased risk, but not as high as for those living inside the 200 foot line.

The research, published in the British Medical Journal, involved 29,000 children suffering from cancer. The Oxford research team said it plans to study the issue further.

There have long been concerns about the possible connection between exposure to high voltage electricity and the risk of cancer. John E. Moulder, Professor of Radiation Oncology at the Medical College of Wisconsin, says there have been several studies of people working in "electrical" occupations.

"Some of these studies appear to show a weak association between exposure to power-frequency magnetic fields and the incidence of some cancers. However, laboratory studies have shown little evidence of a link between power-frequency fields and cancer," he wrote in a posting on his Web site.

The Web site "QuackWatch" also throws cold water on the notion of a power line-cancer link.

"The notion that electric power lines can cause cancer arose in 1979 with a single flawed epidemiological study that created a stir. Subsequent epidemiologic and animal studies have failed to find a consistent and significant effect. No plausible mechanism linking power lines and cancer has been found. In recent years, the verdict from large-scale scientific studies has been conclusively negative, and scientific and medical societies have issued official statements that power lines are not a significant health risk. In short, there is nothing to worry about," writes John W. Farley, Professor of Physics at the University of Nevada, Las Vegas.

Leukemia is the most common cancer of childhood. The body produces lymphocytes to protect the body from infection; in leukemia these cells do not mature properly and become too numerous in the blood and bone marrow. Leukemia researchers say it's not clear what causes the disease.