The controversial theory that electric fields like those around power lines can cause cancer is getting a boost from a National Institutes of Health scientific panel.
Though divided, the group voted this week that such electromagnetic fields should be considered "possible human carcinogens.""This report does not suggest the risk is high," said Michael Gallo, chairman of the group.
Indeed, the risk "is probably quite small compared to many other public health risks," said Gallo, a professor at the University of Medicine and Dentistry of New Jersey-Robert Wood Medical School in Piscataway.
The new report comes from a National Institutes of Environmental Health Sciences panel convened to review scientific research on electromagnetic fields.
Completing 10 days of discussions in Brooklyn Park, Minn., the group voted 19-9 on Wednesday that electromagnetic fields should be regarded a potential cause of cancer.
Eight members said that, because of conflicting studies, they could not decide whether electrical fields were potential cancer causers. One said they probably are not.
Linda Schoumacher of the Edison Electric Institute, which represents the electrical industry, said it would be premature to comment on the report but that her organization will study it.
The new finding is at odds with a 1996 report by a National Research Council panel of scientists who evaluated about 500 studies on the health effects of high voltage power lines and found "no conclusive and consistent evidence" that electric and magnetic fields cause any human disease.
Studies of the incidence of disease analyzed by the new NIH group found a slight increase in childhood leukemia risk for youngsters whose homes are near power lines and an increase in chronic leukemia in adults working in industries where they are exposed to intensive electric fields.
The group said there wasn't enough evidence to link household exposure to power lines to cancer in adults or to associate electromagnetic fields to such diseases as Alzheimer's disease, depression and birth defects.
They found no evidence of abortion from video display terminals and no evidence of illness other than leukemia in children.
The panel said it looked at hundreds of studies of animals and cells exposed to electric fields that showed little or no effect, raising some concern about the "weak association" found in the epidemiological studies, which look at the incidence of illness.
The earlier National Research Council report noted that some studies had found a "weak, but statistically significant" link between high voltage electrical transmission lines and the incidence of a rare childhood leukemia. But that committee found the research to be flawed.
A 1979 study in Denver that found a group of children who died of leukemia were more likely to live near electrical lines than other youngsters fueled public worry about electrical fields.
The increasing concern prompted Congress in 1992 to fund a research program into electromagnetic fields.