Dr. Devra Davis
(Credit: Environmental Health Trust)Throughout my seven years of reviewing cell phones and covering the wireless industry for CNET, the issue of a possible link between cell phones and brain cancer has surfaced every few months. And as my colleague Marguerite Reardon explains in her comprehensive feature, the debate isn't going away anytime soon. Indeed, research abounds on the subject, and there are plenty of voices on both sides. Some say there's nothing to worry about, and others recommend proceeding with care.
One voice on the cautionary side is Dr. Devra Davis, the author of the 2010 book "Disconnect: The Truth about Cell Phone Radiation, What the Industry Has Done to Hide it and How to Protect Your Family." An epidemiologist and environmental health researcher, Davis is a founding director of the toxicology and environmental studies board of the National Academy of Sciences and founder of the Environmental Health Trust. Davis argues that cell phone use can have very real effects on health, and that cancer is only part of the story.
A few months ago, I interviewed Dr. Davis after reading her book. Though I can tell you a lot about cell phones, I'm not a scientist, and frankly, I wasn't very good at science in school. Yet, I approached the subject with a genuine curiosity, and I was glad to see that Davis breaks down her arguments in a manner that's easy to follow. The material is accessible and digestible, even if it's a bit scattered in places. And though the book's title is over the top, Davis takes a more measured tone inside. She's no alarmist, but she forcefully advocates that more research is needed. And while she does use a cell phone regularly, she also suggests that cell phone users take small steps to reduce radio frequency (RF) energy.
Q: What is the one thing that you want readers to take away from your book Davis: If we fail to pay attention to experimental evidence, we're treating people as subjects in an experiment with no controls. And if we say that we'll accept that cell phone radiation is harmful only when we have enough sick or dead people, then we're dooming three generations to illness.
The chapter that I think is most important is the one that discusses the effects on male reproductive health. A phone in a pocket may be linked to lower sperm count. This is not a confirmed association, but I've talked to several urologists who have begun to advise men that they should not keep the phone in their pocket if they're concerned about libido or impotence. That's not to say that they're the cause of impotence' like everything else in health, it's multifactorial and there can be multiple explanations.
How did you first become interested in this issue Davis: About six years ago my grandson was born. I saw the incredible enthusiasm he had toward a cell phone, and I began to wonder about its safety. Later, I worked for Dr. Ronald Herbermann at the Center for Environmental Oncology at the University of Pittsburgh. I was stunned by what I found.
In your opinion, what is the most significant study on cell phone radiation Davis: I think that there is no single study that is "the most significant," and this is due to the fact that each study uses a particular approach, methodology, or "angle" to ask a biological question. However, there are several studies, that when taken together, all found that the nonionizing radiation that cell phones produce causes biological perturbations in live organisms.
[Editor's note: Shortly after this interview, researchers at the National Institutes of Health found that in healthy volunteer participants, cell phone exposure was associated with increased metabolism of glucose in the region of the brain closest to the antenna. At the time, Davis told CNET that the "stunning" study demonstrated that "cell phone use affects brain activity" and that it "was as close as you can get to a biopsy on a living brain."]
You wrote that the incidence of brain tumors is increasing in Americans aged 20 to 40. Couldn't there be other contributing stimuli beyond cell phones Davis: There's almost no environmental cause that we know, that causes an increase [of brain cancer] in the population within 10 years--not tobacco, not asbestos, not vinyl chloride. The fact that some studies have found a double or more increase in brain tumors of highly exposed users of cell phones I think is very worrisome.
But you understand that some people will debate that finding, correct Davis: I understand that science can make mistakes. But I don't want to see people die. If you hold it to the standard of human proof alone, we don't have the full story yet. But if you do what I think we should do as a modern civilization, then we should rely on the full panoply of science. Sperm exposed to cell phone radiation die three times faster. This can't be a good thing.
When do we decide that a correlation indicates causation Davis: That decision is not merely a scientific decision of rules of inference and deduction, but ultimately a policy decision. Think about the history of tobacco, asbestos, and hormone replacement therapy. Can anyone seriously suggest that we acted appropriately when discussing the danger in those cases In fact, only after overwhelming evidence of human tragedy mounted was action finally taken. And we are paying the price today for failing to take precautionary policies in the form of avoidable deaths around the world.
You recommend that consumers limit their exposure by using headsets, for example, and that they not carry their phone for long periods close to the body. Those steps won't always be practical for some users, so what else would you like to see happen Davis: I'm confident that we can design our way out of this problem. We can better design phones to reduce radiation exposure, and there are ways for consumers to check their phone's signal. For example, there's a Tawkon app that lets users see when their phone has a weak signal.
Why should users care when their phone has a low signal Davis: People don't know those things. They don't realize that when the signal is weak, the phone puts out more of a signal to reach a tower and therefore puts out more radiation.
"The CTIA keeps saying what they've said since 1993, which is that studies conclusively show that there's nothing to worry about. Well, let me tell you something: They do not conclusively show that. The few independent studies that are out there indicate that there's a problem. Most of the other studies have been sponsored by industry."But radiation radio frequency is everywhere. We use cordless phones, baby monitors, and Wi-Fi, so we can never really get away from it. Can cell phones be the only point of concern Davis: No, the world is full of radiation. It's not that radiation is bad. But we need to understand it better and be more sensible about what kind of exposure we put ourselves through.
With cell phones in particular, we need to think twice about using them as an electronic pacifier for children. Children have thinner skulls that are more susceptible to radiation penetration. So if you let a child play with a phone, keep it disconnected [from Wi-Fi and the cellular network] so it's not putting out radiation. There are some simple common-sense things we can do.
Consider also that baby monitors use the same 2.4GHz frequency as many cell phones. So if you're going to use one, put it a good distance from the baby. And put the [Wi-Fi] router away from your sleeping area and your baby's room.
Why is it bothersome that the current standards used to test cell phones were developed in the 1990s Davis: Those standards applied to the early analog phones, when few people talked for long, and [they] relied on a test mannequin that stood more than 6 feet tall, weighed 220 pounds, and had an 11-pound head. Most users are smaller and talk much more now than was presumed at the time. Also, specific standards have never been developed for the young brain or toddlers.
The fact is that we are flying blind with respect to such technologies. We know that the brains of infants and children grow rapidly, but never in the past did they encounter the stimulation they now get from cell phones. What the long term impact of this may be remains a matter of speculation and concern, particularly given the ubiquity of the exposures.
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