Over her distinguished career as a scientist, professor, and author, Dr. Devra Davis has racked up her share of laurels. With a Ph.D. in science studies and a post-doctoral Master’s of Public Health in epidemiology, Dr. Davis has worked for the National Academy of Sciences, and as a senior advisor in the US Department of Health and Human Services. She was appointed by former President Bill Clinton to his Chemical Safety and Hazard Mitigation Board. And she served as a lead author of the Intergovernmental Panel on Climate Change, which was awarded the Nobel Prize in 2007 along with former Vice-President Al Gore. She was the founding director of what is reputed to be the world’s first Center for Environmental Oncology at the University of Pittsburgh, and she currently lectures at Harvard University and Georgetown University.

Her book, When Smoke Ran Like Water (Basic Books, 2002), was a finalist for the National Book Award, and her book The Secret History of the War on Cancer (Basic Books, 2009) is being used at major public health universities, including Harvard, Emory, and Tulane.

But it’s her 2010 release, Disconnect: The Truth About Cell Phone Radiation, What the Industry Has Done to Hide It, and How to Protect Your Family (Dutton, 2010), that may put her in the history books as the 21st century’s Rachel Carson. In it, Davis examines the controversy surrounding cell phone use and its possible link to brain cancer and other human health impacts.

Like many of us, Davis was initially skeptical about the ties between cell phone use and cancer. But after spending the past seven years poring over the research, she’s become one of the most vocal and credible voices warning about the dangers of cell phone radiation.

Green America editor Tracy Fernandez Rysavy talked to Dr. Davis about why she’s concerned about widespread cell phone use, and why it’s so vital to protect our children from cell phone radiation, even in the face of some uncertainty of harm.

Green America/Tracy Fernandez Rysavy: What made you start to worry about the connection between cell phones and brain cancer?

Dr. Devra Davis: I initially figured this was just one of those issues that
attracts people who aren’t very credible. There’s a kind of arrogance that those of us who’ve been at the center of American science tend to have: I frankly assumed if there was anything important to know about cell phones and cancer, I would of course know it!

Then I came across a report by Sir William Stewart of the Stewart Commission of Great Britain. Sir William has been the president of the British Association for Science, the president of the Scottish National Academy of Science, and he’s one of Britain’s most distinguished scientists. He was an advisor to Margaret Thatcher. He’s very highly regarded among both conservatives and liberals in England—a scientist’s scientist. And he issued a warning in 2000 that said children should not be using cell phones. I thought, “Well, the British, they’re eccentric, you know.”

Then I got a hold of the report, and I was flabbergasted. Sir William and his colleagues were concerned about the biological properties of cell phone radiation, which I knew nothing about at the time. The report cited studies showing that pulse signals from cell phones could damage DNA and could weaken the blood-brain barrier.

Tracy: So then you looked through seven years’ worth of research on this topic. What have the studies that have found possible links between cell phones and cancer had in common?

Dr. Davis: Every study that’s ever looked at people who’ve used a cell phone heavily for ten years or more finds a doubled risk of brain tumors.

Tracy: Every study?

Dr. Davis: Yes. Including the industry-sponsored ones, and there aren't that many of those.

The majority of studies on cell phones and brain cancer have been negative— they’ve not found anything. Those studies have defined a user as a person who averaged one call a week for six months. And the average person in the study used a phone for less than six years. Brain cancer takes a minimum of ten years to develop. So if you’re studying a bunch of people who’ve made very few phone calls and have used a phone for a very short period of time, of course you’re not going to find anything. It would be shocking if you did.

Today, three out of every four children under 12 uses a cell phone, and many households have eliminated their landlines and use cell phones exclusively. There are now nearly five billion cell phones in use worldwide.

Another thing those studies have had in common is that they’ve almost all been independently funded. In other words, when funding comes from industry, it really tends to discourage results from being positive in terms of a link between cell phones and brain cancer. Now that’s not to say that everybody who works for industry is on the take. But there are these subtle ways in which it affects conclusions.

There’s a general reluctance on the part of scientists to agree that something is a problem, because then their research might be over. So the more uncertainty we can find, the more we need to continue doing the research. Uncertainty becomes a very convenient thing to perpetuate.

I say this as someone who’s worked in science for more than 30 years. In the cases of asbestos and passive smoking, which I was involved in leading studies of at the National Academy of Sciences, it was a tremendous struggle before we could get results released suggesting there was a problem. The struggle arose not because of debates about the science of these hazards, but because of the political and economic influence of these highly profitable industries.

Tracy: You’re not the first person I’ve heard compare the studies on cell phones and brain cancer to the struggle to prove that tobacco and asbestos caused harm.

Dr. Davis: In both of those situations, I noticed a pattern: First you’d have reports of harm of people. And then industry steps in to raise doubt of that harm.

Now with the publication of the tobacco papers, we have evidence of what went on, which is a campaign where the tobacco companies exaggerated doubt so they could keep selling their products. A book by Dr. David Michaels called Doubt Is Their Product (Oxford University Press, 2008) talks about a phrase that appeared in a memo from the tobacco industry referring to the idea that smoking caused lung cancer:

“As long as we can raise questions in people’s minds, then we’ve succeeded.” That’s the modus operandi here: raise doubt, confuse people.

Tracy: Let’s get more specific about how cell phone radiation can damage DNA. There’s a belief out there—which was published last fall in Scientific American—that cell phone radiation can’t cause cancer, because it’s non-ionizing radiation.

Dr. Davis: That was a very unusual piece for Scientific American to run on several accounts, one of which was that it used language that science usually doesn’t use. It said that it’s “physically impossible” for cell phone radiation to have a biological effect that causes cancer, because it doesn’t damage DNA by breaking chemical bonds.

Let’s break that sentence down. First of all, yes, it’s certainly true that cell phone radiation is too weak to break DNA. No one has ever suggested that it does so like X-rays. In fact, X-rays are ionizing radiation. That means they break the chemical bonds that hold things together.

Non-ionizing radiation, by definition, cannot do that. That doesn’t mean that it’s safe. It may damage DNA in other ways. The amount of power in a cell phone is several thousand times weaker than that of a microwave oven, but they both use the same frequency. A microwave oven will boil a cup of water in two minutes. And cell phones are being held next to your brain for hours a day.

Studies are showing that cell-phone radiation produces free radicals that we know can cause damage. It is destabilizing DNA, impairing the ability of DNA to repair itself. And we know it’s causing weakening of the blood-brain barrier and weakening of cell membranes. All of these are biological impacts that can lead to cancer.

We also know you can get cancer without damaging DNA, as what happens with asbestos and hormone replacement therapy; these two agents cause cancer but do not directly damage DNA. So this idea that you can’t have cancer because you don’t damage DNA is wrong, on its face.

Finally, we know that cell phone radiation has profound biological effects from studies that have been done in cell cultures in animals and some experimental studies on humans. For all of those reasons, the Scientific American article was really mistaken. It’s incredible that it took such a strong tone.

Tracy: I want to go back to the blood-brain barrier, because I thought that was so important when I read your book. Can you explain what it is, and how cell phone radiation affects it?

Dr. Davis: The blood-brain barrier is a natural barrier that protects the brain from undesirable materials that could enter it through the bloodstream.

I talked to Dr. Allan Frey for my book, who performed a study involving the blood-brain barrier with the Office of Naval Research. What he basically did was to take a rat, inject blue dye into its veins, and show that while everything else inside the rat turned blue, the blue dye didn’t get into the brain. That showed
we have a blood-brain barrier protecting the brain.

Then what he did was to perform the same experiment exposing the rat to a microwave-sized, pulsed digital radiofrequency signal before injecting the dye—and the brain turned blue. That was pretty powerful.

And then he was told by his superiors to stop working in that area if he expected to continue getting support for his research. Well, a pseudo-replication of this study was done by a group connected to industry where they injected the dye into the abdomen, not into the bloodstream. The brain, of course, didn’t turn blue, so they concluded that Frey was wrong. That’s the kind of misleading science that has characterized this field.

The blood-brain barrier work, by the way, is really relevant to Green America’s work on toxins. Since radio-frequency radiation weakens the blood-brain barrier, that means you will enhance the uptake of toxicants through the brain by using a cell phone. So all of our policies to protect us from toxins will do nothing if we do not also deal with this exposure.

Tracy: Why is it that we have to worry most about children and cell phones?

Dr. Davis: Children are not just little adults. They have thinner brains, they have thinner skulls, and their brains contain more fluid. The more fluid something contains, the more vulnerable it is to microwave radiation. After all, a cell phone is just a small, two-way microwave radio.

Children today are growing up in a sea of radio-frequency radiation that did not exist even five years ago. They need to be protected.

Tracy: I was surprised to learn that men who’d like to become fathers also need to be careful of cell phone use.

Dr. Davis: Yes. If you take sperm from healthy men and split it into two samples, it will die naturally, because sperm don’t live that long. But sperm exposed to cell phone radiation will die four times faster, and they will develop biological signs of damage that we know indicate they’ve been harmed.

Studies showing sperm damage in human males have been done by leading researchers in Australia, in Greece, in Turkey, and in the US at the Cleveland Clinic. In addition, studies have followed men who have reduced sperm count and found that those who use their phone for four hours a day have half the spermcount of others.

Finally, studies in Greece have shown that exposing fruit flies to cell phone radiation doesn’t kill them. But when you expose them and then magnify them under a microscope, you can see that their testes and ovaries are shrunken.

These studies have also led to researchers raising the issue of whether cell phone radiation has anything to do with the hive collapse phenomenon that’s endangering honeybees.

Tracy: One thing you point out in your book that I think people don’t realize is that industry is issuing warnings about cell phone radiation and human health—though very quietly.

Dr. Davis: The ultimate indication of this now comes from the insurance industry. You cannot buy secondary insurance for cell phone damages from Lloyds of London, Swiss Re, or many of the companies that provide this insurance.

And the cell phone companies are all issuing fine-print warnings in the paperwork that comes with all the smart phones. What are you supposed to do if you have an iPhone 4 that says you can’t put it into your pocket without exceeding the FCC exposure guidelines?

Tracy: And many of the warnings also recommend holding your cell phone about an inch from your head.

Dr. Davis: Yes, go ahead and try getting everyone to do that.

Tracy: I know your campaign (EnvironmentalHealthTrust.org) is asking for more visible warnings directly on the phones themselves. What would this accomplish?

Dr. Davis: It would accomplish two things: First, people would have to look at this warning every time they picked up their phone and think about how they have to keep it away from their body and their brain.

Second, it would also help the phone companies reduce their liability, so it’s not a losing proposition for them.

Tracy: Would it also push them to create safer phones, too?

Dr. Davis: Yes. The newer phones now have the antennas on the back, pointing away from the body when you talk on them. That feature is safer than in the past, when the antennas were on the front.

But the newer phones are also more dangerous, because if you turn that phone and keep it in your pocket with the antennas pointing toward your body, as that phone is searching for a signal— which is what they do when they’re on—it’s pumping radiation into you.

Plus, studies indicate that the newer 3G and 4G phones may be even more harmful than the 2G phones. [Editor’s note: One 2008 study cited in Davis’ book found a ten times higher rate of damaged DNA in human cells exposed to radio-frequency radiation from 3G phones compared to 2G phones.]

Tracy: Can they make a low-radiation phone that isn’t as much of a concern, or is any radiation bad for us?

Dr. Davis: They can make very low-radiation phones. But there’s no guarantee of safety, no matter how low the radiation is, if you’re going to use the phone next to your head for hours.

Tracy: How problematic is the fact that when the FCC [Federal Communications Commission] establishes threshold safety levels for radiation exposure from cell phones, it’s basing them on the SAM model?

Dr. Davis: SAM stands for “standard anthropomorphic male,” and he was taken from the top ten percent of military recruits in the 1989. He was six-foot-three, weighed 220 pounds, and had an 11-pound head. Most people in the world do not have SAM’s head. Radiation goes more deeply into a smaller head than a larger one. And today, three out of every four 12- year-olds, and half of all ten-year-olds, have a cell phone.

Plus, the safety standards for cell phones also presume calls last only up to six minutes. Our heads—especially children’s heads—are getting a lot more exposure than SAM would get. We need a major revision of the safety standards that takes into account that billions of cell phone users are much smaller and younger than SAM.

Tracy: One thing in your book that really worried me was that cordless home phones are emitting similar radiation to cell phones.

Dr. Davis: Yes. And the base station is radiating all the time. When you hold the handset next to your head, you’re getting a whopping dose. We recommend that people not use cordless phones, and certainly not have the base station close to your bed.

Tracy: Which, of course, is where mine has been.

Dr. Davis: Which is where most people’s is. I’ve actually replaced my cordless phones with corded landlines.

In France, people are starting to buy them more, and the Israelis have recommended that people replace their cordless phones with corded phones.

The good news is that experimental studies show that good nutrition— literally exposing animals or cells to the natural hormone melatonin or vitamins A, E, or C before you expose them to radiofrequency radiation—may help repairdamage. So whatever you have done in the past, go forward with good cell phone practices, and good nutrition can help repair past damage.

Tracy: How worried do we have to be about wireless Internet? Is it as much of a worry as cell phones?

Dr. Davis: No, it’s not as big of a worry because we’re not holding the wireless routers against our bodies. But again, distance is your friend. Your routers should not be located in your bedroom or anyplace where your family spends a lot of time. Turning wireless devices off at night makes sense because it protects health, saves energy, and reduces demand for energy grid access. What I’m very concerned about now are children sleeping with phones under their pillows so they can text at night, and young girls are keeping phones in their bras.

Tracy: I didn’t know that was an epidemic!

Dr. Davis: Well, apparently, it’s pretty common among teenagers and athletic women. Several hysicians have contacted me about breast tumors in women right at the site where they’ve kept their phone.

Tracy: Is there anything else you’d like to our readers to know?

Dr. Davis: Those of us working in this field want to encourage safer design. We want to encourage people to use cell phones in a safer way and to encourage more corporate responsibility. I am pleased that the businesses joining our Business Campaign for Safer Cell Phones are agreeing to provide headsets and simple warnings to all their employees. That’s why I wrote my book and why I’m speaking around the world.

And I do think people need to use their phones less. I realize that cell phones are going to be driving economic forces. It’s not like I want people to turn off their phones. It’s not realistic. But we really do need a national conversation and a cultural change about a lot of aspects of cell phone use.