As you read this, your body is bathed in an electromagnetic field that matches the frequency of the power supply that pervades the United States.
Because our bodies conduct electricity, these fields we encounter at home or work induce tiny electrical currents in our bodies which, like the field, alternate 60 times a second.
A possible health risk? The question is attracting millions in research money and has electric utilities worried about implications.
Scientists have known about these electromagnetic fields ever since the country plugged into electricity. The fields in your home can be generated by hair dryers, mixers, kitchen ranges, electric blankets, power lines on the street, televisions, computers, even by the electricity your next-door neighbor is using.
But the fields are weak, a million times lower than levels proved to damage plants or animals.
”To engineers and physicists, it has seemed absolutely impossible that these fields could be harmful,” says Arthur W. Guy, director of the University of Washington`s Bioelectromagnetics Research Laboratory.
But a few studies in recent years have dropped like bombshells onto a society that has become dependent on electricity. The first was a 1979 study in Denver that found that children with leukemia were two to three times more likely to have lived near neighborhood power lines.
That study was criticized for estimating rather than actually measuring the magnetic fields in the children`s homes. But a follow-up study, in which fields were measured and estimated, found almost the same effects.
Studies worldwide followed. Guy estimates he has 10,000 reports in his files. Most, including one in Seattle seeking a correlation between adult leukemia and proximity to power lines, found nothing.
Yet scattered reports have continued to suggest a connection between disease and electromagnetic fields: no proof, no direct cause-and-effect, just suggestions.
Sam Milham, epidemiologist for the state of Washington, reported in 1982 that workers exposed to electromagnetic fields on the job were slightly more likely to die of leukemia than workers in other occupations. The report was based only on a comparison of job titles with death causes. It did not consider other hazards the workers might have been exposed to.
But Milham says the study`s conclusions are holding up. Since Milham`s report, several other studies have shown similarly tiny increases of leukemia cases among electrical workers.
There are contradictions in the research. Laboratory experiments have shown that weak electromagnetic fields can affect living things. But the results sometimes are good, as in stimulating the healing of broken bones. And the results-good or bad-seem to occur only at certain frequencies and intensities.
”But we`re at a point where reasonable people would say we know there`s something going on even if we don`t know how it works or whether it necessarily is a hazard,” says Stephen Cleary, a biophysicist at the Medical College of Virginia.
Most research in the field is paid for by the Electric Power Research Institute, the research arm of the electrical industry. Projects range from laboratory experiments to a new study of children`s cancer and power lines in Los Angeles County, and a study of East Coast telephone workers in utility tunnels where they are exposed to electromagnetic fields.
Guy estimates it will be three years before laboratory studies yield results and twice that long for the field studies of children and electrical workers. ”In the meantime it makes sense to hold the status quo, not let the electromagnetic fields go any higher,” he said.
Budget cuts have caused the Environmental Protection Agency to phase out most of its research in the health effects of electromagnetic fields.
”Other federal agencies are pressuring the EPA to resume the work, but they say they`re not going to do it,” says Louis Slesin, editor and publisher of Microwave News in New York. ”We`re not talking of very much money (about $1 million a year and five staffers).”
Slesin is critical that the Electric Power Research Institute, funded by the electrical industry, is performing most of the research into
electromagnetic hazards.
”I think EPRI has a role to play, but it shouldn`t be the only role because it is the classic interested party. The health-based federal agencies should be in the picture, and they`re not.” (There are no federal regulations that limit electromagnetic fields generated by power lines.)
Of the pervasiveness of electromagnetic fields, Slesin says: ”This is the stuff of the information age, and it is everywhere. There is as much chance of eliminating it as there is of putting the atomic genie back into the bottle.”
Basic change needed
Some scientists believe that only a ”conceptual breakthrough” in the way electricity is generated, distributed and used can solve the problem of electromagnetic fields.
David Savitz of the University of North Carolina at Chapel Hill, who confirmed the Denver study linking power lines with childhood leukemia, says studies are not yet sufficiently convincing to warrant drastic action by homeowners.
”The only readily changed personal exposure to magnetic fields would be through avoidance of electric blankets or heated waterbeds,” he said.
Savitz adds that even if the risk of power-line-induced leukemia in children turns out to be real, it would mean only one or two additional cases in 10,000 children a year.
The currents induced in human bodies by magnetic fields are much weaker than the body`s natural electrical activity in the brain and heart. It increases the difficulty of explaining how such weak effects could cause biological changes.
However, W. Ross Adey of the Loma Linda School of Medicine believes he has found a mechanism by which a very weak signal can trigger a series of reactions that might promote cancer by leading to unregulated cell growth.
The cell membrane, Adey explains, has a huge electrical gradient across it. A ”very, very weak signal at some point along the membrane can trigger a tremendous increase in the amount of energy released at the surface of the cell,” he says.
The result, Adey says, could be a disruption in communication within and between cells causing them to begin growing out of control. But the cells appear to be sensitive only to signals in ”certain narrow frequency bands, and certain narrow intensity ranges,” Adey says. Adey`s work is
controversial. Other researchers have been unable to replicate some of it.
Avoid power lines
So what should the public do while it awaits the answers, which may be a half dozen years away?
Slesin, who earned a doctorate at the Massachusetts Institute of Technology in environmental-risk analysis, points out possible economic hazards. ”Perception of risk works its own mysterious ways, sometimes not having much to do with reality,” he says. ”The impact on utilities could be tremendous.
”As for the public, buying a house is the largest investment many people make in a lifetime. They might want to consider the repercussions (of nearby power lines) if this turns out to be a high-visibility issue.”
