Physicists offer reassurances on EMF.

The public has overreacted to reports linking electromagnetic fields (EMFs) to cancer, declares the 43,000-member American Physical Society in a new policy statement. More than $23 billion has already been spent to minimize exposure to these fields -- principally to alter the placement of power lines or the proximity of buildings to them, according to an accompanying background paper.

Many studies over the past 16 years have found hints of an above-average cancer risk within certain populations of workers and children exposed to EMFs. However, the APS statement notes, these studies have failed not only to link a consistent group of cancers to EMFs, but also to identify a plausible biophysical mechanism by which these power-line fields might foster cancer.

"The diversion of these [billions of dollars] to eliminate a threat which has no persuasive scientific basis is disturbing," the APS statement says. Moreover, it argues, "more serious environmental problems are neglected for lack of funding and public attention, and the burden of cost . . . is incommensurate with the risk, if any."

Why issue such a policy statement now?

"We've been tracking this for almost 7 years," says Robert Park in APS' Washington, D.C., office. "And all this time we've been watching as the epidemiology got fainter...and one proposed mechanism after another got shot down. Yet public concern [over EMFs and power lines] seemed to be rising. So we decided to take some action."

Park says the new policy "would stop short of saying there's no reason to continue research" in this area.

Epidemiologist David A. Savitz of the University of North Carolina at Chapel Hill agrees that "we don't know with these fields whether there's any risk at any level." However, he adds, "if you take studies that I and others have been involved with -- and take their findings literally -- they suggest there's a hazard at exposure levels that we currently live with." So if the cancer-EMF link proves real, merely avoiding extreme exposures may not be sufficient to eliminate risk, he says.

"That makes the policy options quite difficult," he says, and suggests that adopting no- or low-cost measures for prudent avoidance may make sense.

Park, by contrast, argues that "this whole argument about prudent avoidance has been terribly detrimental." He says the public has misinterpreted it to mean that there is some risk, not merely the possibility of risk.