The jury is still out on whether living near power lines is bad for your health. A study by Swedish researchers finds that cases of childhood leukemia doubled for those living within 500 feet of high-voltage lines. The scientists found 325 cases in 400,000 people, although they cautioned that they did not attempt to establish causality. A second study, however, by the US government finds no association between power lines and all types of childhood cancer. The lead author of the report, Martha Linet of the US National Cancer Institute in Washington, says the work "pretty resoundingly finds no association" between the two.