Cell Phone Paranoia Exposed
The physics behind the interaction of radiation and matter tells us that cell phones cannot cause cancer. So why does the idea persist? We dig into the history of radiation and cancer to find out why.
Note: it is best to read Do Cell Phones Cause Cancer? and Cell Phone Update before reading this article.
Cell Phone Radiation and Heating the Brain
I recently published an op-ed piece in the Pittsburgh Post-Gazette decrying the hullabaloo being raised about cell phones causing brain cancer. In brief: cell phone radiation is much too feeble to directly damage DNA (this is the usual way radiation causes cancer). What it does do is jostle the molecules in brain tissue. Jostled molecules are better known as heated molecules. Thus the physics of radiation tells us that the biology of radiation damage is the biology of heat damage.Of course too much heat is not a good thing. I would not be happy if my cell phone were slow-cooking my brain. But what levels of heating are we talking about? Heat energy deposited in tissue is measured as "SAR", which stands for "specific absorption rate". This tells us how many joules of energy are deposited in tissue per second per kilogram of tissue. The units for this are watts per kilogram, written as W/kg. In the US cell phones are not permitted to have SAR ratings of over 1.6 W/kg as measured in any 1/1000 of a kg in the brain (this is about 1 cubic centimeter of tissue) [*]. Now the brain naturally produces its own heat just by running all that high-powered thinking ability. The heat output from standing there thinking is about 15 W/kg, about ten times what the cell phone contributes. If you go outside into the sunlight and you are not wearing a hat, your head will pick up about 20 W/kg of extra heat energy. The upshot is that the cell phone is making a fairly small contribution to the heat budget of your brain. Can this cause cancer?
The brain has evolved over hundreds of thousands of years in a thermal environment, namely it is warm. The survival of the species then depends on the stability of biological processes under the jostling due to thermal energies that we are likely to experience in a lifetime. Run hard from a saber tooth tiger and your brain will warm up. Argue with your wife over who gets to eat the giant sloth bone, and your brain will warm up. Spend the night sleeping outside of the cave, and your brain will cool down. The brain can handle it, and it doesn't get cancer.
Brain Cancer
OK, let's assume cell phones cause brain cancer. Let's check the figures. In 1985 when nobody used a cell phone there were 6.9 deaths from brain cancer per 100,000 people. In 2005, when everyone used a cell phone, there were 6.5 deaths from brain cancer per 100,000. You do the math. Forget that, I'll do the math: fewer people are dying from brain cancer!
We've Seen it all Before!
Do you remember the power line fiasco of the 1980s and 90s? The idea was that the magnetic fields from power lines (and computer monitors and the wiring in your house) caused cancer. The National Academy of Sciences reviewed the published literature and announced that power line radiation led to an increase in the rate of leukemia by a factor of two. But it was all bad science. The studies upon which the distinguished Academicians based their decision were riddled with bias.
experimental bias
Imagine that you want to find out if power lines cause leukemia. You find little Jimmy has leukemia and go to visit his house. You ask, "Do you live near a power line?". "No", "Are you sure?", "I think I lived near one in my previous house". You put a little check next to Jimmy's name. You have just introduced observer bias into your experiment. As a researcher you are a little attached to the project you have been working on for two years. And you know that Jimmy has leukemia, surely he lived near a power line at some time.
On top of this, Jimmy has introduced recall bias into the experiment. He has leukemia, there must be a reason he got it. The guy in the lab coat in front of him seems to be implying that it has something to do with power lines and he heard something like that on the news a while ago, and, yeah, he does kinda remember a power line near his old house!
You see the problem. A good experiment avoids these issues by running a "blind" experiment. This means, for example, that the researcher should not know if the person he is interviewing has leukemia or not. Recall bias can be avoided by actually measuring the strength of magnetic fields in houses of leukemia sufferers and a control group of people who have no cancer.
In the case of power lines, such blinded experiments were eventually performed. No surprise here: the evidence for higher leukemia rates vanished. Power lines don't cause cancer.
Its easy to dismiss the whole saga as a nuisance for a minority of people. But it wasn't -- there are estimates that the power line fiasco cost American taxpayers twenty billion dollars. That's $300 of our tax money per family.
There are Studies and there are "Studies"
After the humiliating and expensive experience with power lines, things must be better now, right? Well, maybe not. The European Union has spent $24 million conducting an enormous study of the correlation of cell phone use with the incidence of brain cancer, called the Interphone Study. Remember, everyone uses cell phones, so to show an effect you have to show that people who use cell phones more tend to get brain cancer more. Brain cancer is a rare disease, so these numbers have to be collected very carefully. Are they? Not even close.Imagine you are a cancer researcher in Sweden, you go to the hospital to interview poor Mrs. Sundstrom who is dying from brain cancer. You ask her, "How much did you use your cell phone?" "Oh, not much". "Are you sure?", "Well I did use it quite a bit when I was trying to corner the pickled herring market.". Its our old friend observer bias. And Mrs. Sundstrom sees a man in a white coat in front of her asking about cell phones, and she's heard something on the news about cell phones, and there's got to be a reason she got brain cancer. Yep: recall bias.
It is difficult to know if the Interphone Study group has implemented blind methodology to avoid observer bias. However, there are published reports stating that the study suffers from recall bias. The researchers are asking cancer victims about their cell phone use, not measuring it (say, via provider records). As a result the researchers are arguing amongst themselves, and the publication of the report has been delayed by nearly three years.
In an attempt to paper over the cracks, Interphone is trying to compare people's recall of cell phone usage with actual cell phone usage. Can they actually account for the different recall between healthy and cancerous people? Can they do it with any accuracy? It seems unlikely for a number that is already difficult to tease out of the data. The upshot is that the Interphone Study is rife with experimental bias. They may as well have flushed $24 million bucks down the john.
Will cell phones end up costing us another $20 billion? George Santayana famously said
"Those who cannot remember the past are condemned to repeat it."In this case it looks like a more accurate version would be
"Those who can remember the past, but choose to ignore it, will enforce repetition of it on the rest of us."
Cell Phone Cancer Conspiracy Theorists
The real issue here is why is there so much bleating over cell phones and cancer?The answer lies in a complex mix of bad science and human frailty. We've already discussed how bad science can scuttle attempts to learn the truth of complicated issues, let's look at the human side of the equation.
Some True Believers really do think that cell phones cause cancer. Smart people tell them that they do! And what about all the studies? And their [insert relative here] died from a brain tumor and he was on the cell phone all the time! Sadly, its probably the last cause that has the most influence. The fact is that people get brain cancer. And everyone uses a cell phone. And it is human nature to look for causes and patterns in our lives. And cell phones are an easy target. Heck, I wouldn't mind if it were true so that I could cash in on the class action suit, but it ain't.
There are doctors who are True Believers. The problem here is that researchers tend to be attached to their pet ideas and can be remarkably stubborn in the face of contrary evidence. Doctors are people too, after all, and one must expect this. And in a sense its not bad, perseverance is a good quality to have when doing research.
More disturbing is the trend to New Ageism that I detect in cancerous cell phone True Believers.
The Pittsburgh Cell Phone Fatwa
Dr. Ronald Herberman, the distinguished head of the University of Pittsburgh Medical Center (UPMC) Cancer Center and the University of Pittsburgh Cancer Institute, recently issued a highly publicized internal memorandum warning staff members of the health risks of cell phones. The drive to issue the fatwa came from Dr. Devra Davis, director of the University of Pittsburgh's Center for Environmental Oncology. Davis holds a B.S. in physiological psychology and an M.A. in sociology from the University of Pittsburgh. According to her web site she completed a Ph.D. in "science studies" at the University of Chicago and has a Masters in Public Health. Hang on a sec, what is "science studies"? I'm not sure, but her Ph.D. thesis was on the conceptualizations of religion and science in the work of Immanuel Kant and Auguste Comte. Usually philosophers end up driving cabs, so she's done quite well for herself.Dr. Davis is also an author. Her latest book is The Secret History of the War on Cancer. A secret history, how exciting! I looked up the review of this book in The New Republic. Here is part of what the reviewer had to say:
"The Secret History of the War on Cancer is a hysterical and exasperating book. It has no overall structure and it repeats itself in the sloppiest ways. It meanders into stories and themes that have no obvious pertinence to cancer and the war on cancer. And worst of all -- this being a protest, after all, against the state of medicine and science -- are its New Age tones. A well-trained and reputable cancer epidemiologist might be expected to produce a book based on research and data rather than unsubstantiated claims and anecdotes. But throughout The Secret History of the War on Cancer there is a continuing homage to "treatments" that have not even been subject to serious research, much less proved safe or effective."Whew! I'm glad I didn't say that, because I'm sure I would be in a lot of trouble!
Dr. Davis and I exchanged some emails about cell phones and cancer and she kindly pointed me to the Bio Initiative web site. What I found there was a dozen angry doctors giving a long list of the woes that low energy radiation causes. And at the end of this list I found Louis Slesin.
Microwave News
Dr. Louis Slesin is the founding editor of Microwave News, a newsletter and blog carrying on the good fight against the evils of low energy radiation. As usual, his credentials are impeccable: he got his MA in Chemical Physics from Columbia and a Ph.D. in Environmental Policy from MIT. But we have learned that credentials don't mean much in this game. Slesin is a strong (to this day) proponent of the discredited idea that power lines cause cancer (and Lou Gerhig's disease and miscarriages). What does an old anti-power-line warrior do? He upgrades to cell phones!There was a time when zealots who were painted into a corner would fling themselves off of the parapets. Now it seems they merely airlift to a new castle and carry on the struggle.
More Secrets
One of the more vociferous members of Interphone is Dr. Lennart Hardell. Dr. Hardell is a professor of oncology for University Hospital in Orebro, Sweden. He says"By now, evaluating all international studies in this area, there is a consistent pattern of a nearly doubled risk for brain tumors (glioma and acoustic neuroma) on the side of the head where a mobile phone has been used for at least 10 years"Wow, that's pretty definitive! But he is talking about part of the famed and flawed Interphone study. The same one that is riddled with recall bias and internal rife.
It gets better. Dr. Hardell is the principle author of Secret Ties to Industry and Conflicting Interests in Cancer Research. Another book about secrets and cancer? Do these people have a club or something?
The French Fatwa
On June 20, 2008 twenty French cancer and public health specialists issued a public appeal in the Journal du Dimanche calling for prudence in cell phone use. The organizing force for the appeal was Dr. David Servan-Schreiber. Dr. Servan-Schreiber obtained his MD from the University of Laval and a Ph.D in neuroscience from Carnegie Mellon University. He spends part of his time as a clinical professor of Psychiatry at the University of Pittsburgh. So far so good, but continue reading his biography and you discover that he was director of the Center for Complementary Medicine at the University of Pittsburgh's Shadyside Hospital. Complementary medicine? Like aromatherapy and acupuncture and coffee enemas?Questions fly to the mind: why do cell phones attract the New Age crowd? Why does Pittsburgh attract New Agers? Can crystals really cure impotence? Is my crystal more powerful if I form it into a pyramid shape? And most importantly, why can't I start a wacky institute? How about The Area 54 Institute or The Center for the Investigation for why People Think Gillian Anderson is Hot?
Cell Phone Profiteers
If, at the end of all this, you are still worried about cell phones I would like to suggest that holding it away from your head or only using it for 10 minutes a day is not a solution. They cause brain cancer for goodness sake! Either get rid of the damn thing or make use of one of the many companies that wants to rip you off (presented here for your convenience).
PS. the cell phones popping popcorn video is FAKE. Completely. Even the acting is bad. Sheesh.
[*] There is an oddity in the SAR story. One of the pieces of information I have been able to get on actual SAR rates in the head is a simulation of energy levels. This shows a SAR well above 1.6 at the ear. I'm not sure what's going on here, either the simulation is wrong or fake (not unknown), or the cell phone industry is letting government guidelines slide by (not unknown). On the other hand, the image shown above looks ok.
