After 17 years of controversy, a leading US scientific panel concludes there is no link between power lines and cancer. The National Research Council, part of the congressionally chartered National Academy of Sciences, says there is no convincing evidence that electromagnetic fields (EMFs) from power lines or appliances harm humans. Even so, in an unusual step three of the 23 panellists issued a separate statement emphasising the report has not proven that EMFs are safe. They cited a "reliable, though low, statistical association between power lines and at least one form of cancer." More than 500 studies of the alleged links have been published since the 1970s, when the issue first became controversial.