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HSPH Researcher Says Cell Phone Technology = Safe Technology
Sixty-one million Americans use cell phones. Their calls are transmitted via some of the 52,000 antennas erected over the last decade. Around the country--and the world--many people wonder if they should be worried about harmful health effects from the radio waves emitted by these phones and antennas.
"There are no established health effects from cellular phone radio waves or transmitters that operate within FCC or state guidelines," says HSPH researcher Peter Valberg, adjunct faculty member in the Department of Environmental Health.
Peter Valberg, adjunct
professor in the Department of Environmental Health, measures levels of
radio waves on a Cambridge street with a radio frequency survey meter.
Valberg, who served as a full-time HSPH faculty member for 14 years, now splits his time between teaching and research for HSPH and consulting with Cambridge Environmental, Inc. He serves on the Peer Review Group on Cellular Technology for the Harvard Center for Risk Analysis; he has consulted for the cities of Newton, MA and Pembroke, NH on the safety of cellular phone and high-definition television transmitters; and he speaks to concerned citizens about radio-wave health concerns at public meetings. He knows the literature: "Over the past decades, there have been thousands of experiments examining the effects of radio waves. People have looked at the differences between exposed and control groups of animals; others have performed epidemiologic research, and others have looked at isolated cell systems.
"Two things have become apparent," he says. "One, intense radio waves do produce an effect on biological organisms. These effects arise from changing the temperature of the cells." These findings led to the formulation of existing federal and state standards, which reduced the allowable level of exposure by a factor of 10 for occupational exposures and by a level of 50 for public exposure. These and similar international standards have been endorsed by scientific panels from the American National Standards Institute, the World Health Organization, the National Radiation Protection Board of Great Britain, and the Royal Society of Canada.
The other thing that research has brought to light: nothing. More precisely, a handful of studies have reported biological effects, but these effects were not reproducible by other researchers. "It's the nature of science," explains Valberg. "When you're examining something close to the limit of detectability, a lot of times you're going to get a result that's an aberration. The validity of that result depends upon other scientists being able to reproduce the result. So far, low-level radio waves have failed to produce a biological effect that can be duplicated by other researchers."
Valberg uses an analogy of being hit by a baseball bat and by a feather to illustrate the difficulty of finding an effect from the low levels of radiation used in cell-phone technology. The baseball bat represents intense radio waves, and the feather stands in for low-level radio waves from cell phones: "When I'm hit by the bat, there's an obvious effectit hurts. But if I'm hit by a feather, is there an effect? Is it a meaningful effect? What if I'm hit by a feather a million times? I can't feel a harmful effect, but I can't say with a hundred percent certainty that there hasn't been one."
Questions about the safety of cell phones come down to levels of certainty and risk assessment. "Despite evidence that there isn't any danger, cell-phone radio waves get a lot of attention because it's a relatively new technology that scares people. But with so many pressing problems in public health--air and water pollution, lead in the environment, violence, cancer, disease, and inadequate health care--things which we know are killing people, it gets a little frustrating that people get worked up over something that's never been proven to harm anyone."
And people do get worked up over radio waves. Just two years ago, a Concord-based activist circulated a petition to block cellular phone company Sprint from activating a cellular phone network. Signatories on that petition included 40 researchers from HSPH and from Boston University School of Public Health. The Boston Globe reported this as if the schools had issued a proclamation against cell phone networks.
"I get hit by this in a lot of public meetings," says Valberg. "People say 'hasn't Harvard issued a statement against radio waves?'" The answer is no, HSPH doesn't issue official statements of this type. What did happen is that individual researchers and faculty members signed a petition that called for further research--not a surprising response from people in a research institution.
Similarly, Valberg, and virtually every other scientist who has studied radio waves and their effect on humans, says more research is necessary. "It's impossible to prove absolute safety. This widespread exposure to radio waves from cell phones, and soon from high-definition television, represents a new technology. As scientists, it's our obligation to examine technology and be as certain as possible that it's safe."
Valberg doesn't use a cell phone himself because, he says, "I don't want to be that accessible." However, he has no fear of the devices. He also points out that radio waves are found in other sources that haven't been worrying people: "I have two kids. My son is fifteen and uses a walkie-talkie. My daughter, who is younger, has a remote control car. I've measured the radio waves from both of these toys and found them to be at higher levels than those found from cell phones. If I had any qualms about the safety of these levels of radio-wave exposure, I certainly wouldn't let my children play with these toys."
