I have a theory about cell phones. . .

I have a theory. I have not done any experimental research to back it up. I’m willing to call it a guess. It is a very well educated guess. Here is my guess: In my lifetime, cell phones will kill more people in this country than cigarettes ever did in my grandparents’ generation.

My grandfather started smoking in the army in Europe during WWII. When he found out it was bad for him, he quit, probably in the early 1960s. He lived to be 86, and did not die of lung cancer. My other grandfather had a friend who started smoking (with her mother!) when she was fourteen years old. She smoked like a champ for 60 years, then quit. She died when she was 94, and the doctors said her lungs were in perfect condition. As you know, most people of their generation who decided to smoke did not have such a good outcome. Many others never did smoke at all, because they weren’t interested, or thought it was disgusting, or because of social or religious pressures. The question we always wanted to ask our grandparents growing up is this: “What kind of insanity did everyone in those days have that made them think that filling their lungs with smoke tens of thousands of times for decades would not eventually kill them?” It seems so obvious in hindsight. Undoubtedly there were some people in those early days who predicted that smoking would kill millions. But no one remembers them. What did my grandparents say? “No one in those days knew it was bad for you.”

I am not very old – under 30. In 2000 when I left college, (a small, private school of about 1000 students), I’ll bet not more than half a dozen students there total had cell phones. I had a lot of friends in college. As far as I ever knew only one of them had a cell phone, and then only the last year we were there. Her dad bought it for her for emergencies while she was driving back and forth between school and home. It was a pay-as-you-go phone, and I think she had 30 minutes a month. I don’t know that she ever used it, and we never knew the number.

In 2003, three years later, I started graduate school. For several months I had a land line and no cell phone. After missing an important research group meeting, I gave in, cancelled the land line, and bought a cell phone. I am sure that now I don’t know anyone under 40 who does not have a cell phone. Most high school students have cell phones.

If I walk across my campus (a major research university) today between classes, I’ll bet at least half of all the students I pass who are not walking with friends have a cell phone clamped to the side of their head. It would be very interesting to find out if it really is half. I don’t have time to run the experiment, but someone should. An average cell phone plan is 600-1000 minutes per month. Most people run out of minutes. That means they are using their cell phones for around 10-15 hours per month.

I am a physicist, almost finished with my PhD. My field is optics. That means I study radiation for a living, specifically radiation-matter interactions. I know a lot about radiation. The radiation I know the most about is optical, meaning it is short wavelength, either in the visible or the near-infrared portion of the electromagnetic spectrum. Cell phones transmit and receive long wavelength radiation. All electromagnetic radiation obeys the same laws, but different parts of the spectrum interact much differently with matter. Here is my theory: lots people who clamp cell phones against their heads for 10-15 hours per month for twenty to thirty years will get brain tumors. Almost everyone who gets a brain tumor will die. I am not aware of any medical condition more deadly and hopeless than a brain tumor. As I said earlier, many people in my grandparents’ generation who smoked didn’t die of lung cancer. The fatality rate due to cell phones will be much higher. Many people in my grandparents’ generation didn’t smoke at all. No one in my generation doesn’t have a cell phone.

I have been saying this for five years now. I have said it to lots of physicists, and lots of non-physicists. No one has ever disagreed with me for scientific reasons. They think it’s an interesting point, but then they get distracted because they have to answer their cell phone. When I first came to grad school I walked into the office of my Electricity and Magnetism professor and asked him. His response was this: “I don’t think so – they wouldn’t be allowed to sell them if they were dangerous.” (Right. You can probably guess his political orientation: a tenured professor at a major research university, and he’s from the UK. The government will take care of us, won’t they? What else are they there for?). He did not address the physics of the question.

OK then, here’s my practical advice: don’t clamp a cell phone against your head for 10-15 hours per month. Should you get rid of your cell phone? Probably. I haven’t, but I’d like to. What can be done? In some good approximation, a cell phone is a point source of radiation. That means the intensity of its field decreases as the inverse of distance squared. In other words, if you move the source twice as far away, the intensity of the field decreases by a factor of four, not by a factor of two. Use the speaker on your cell phone. Better yet, use the wired headset and put the phone as far away from you as it will reach. (Don’t put it in your pocket if you are still young enough to want to have kids).

Here are some common questions I am asked:

What about carrying the cell phone in your pocket when you’re not talking on it? This is probably not as big a deal, because the cell phone is a transmitter and a receiver. It is only transmitting (emitting radiation) significantly when you are talking on it.

Aren’t land lines dangerous too? No. The signal is pretty much confined to the wire (just don’t wrap the cord around your head while you’re talking).

Aren’t cordless phones in the home just as dangerous? Probably not, because they are so much shorter range that the fields they emit don’t have to be as intense. The base for your cordless phone will usually be in your home. The tower your cell phone is communicating with may be miles away. Your cell phone is emitting a field that reaches the closest tower.

But everyone around me has a cell phone, so there’s no way to be safe anyway, right? Remember, the intensity falls off as the inverse of distance squared. Everyone else’s cell phone doesn’t have to be clamped to the side of your head. Maybe it’s like second-hand smoke.

Could I be wrong? It’s possible. Like I said, my specialty is optical radiation. Cell phone frequencies are much lower. They go right through most things, or else your cell phone wouldn’t work indoors. But some of that radiation is absorbed. If it’s clamped to your head, it’s absorbed by your head. How much is absorbed? I don’t know. I don’t know the attenuation coefficient of water at that frequency, which would give a good idea. One thing is for certain, and that is that the higher the intensity, the more absorption. I think cell phones are pretty high intensity, because they have to reach towers that may be miles away.

Radiation is all around us. We can’t escape it. The sun emits lots of visible, IR and UV radiation; the universe is full of cosmic “background” radiation; all bodies of everyday temperatures emit infrared radiation. Most of this doesn’t kill us because it’s not very intense. I think cell phone fields are intense, especially if you integrate the intensity over 10-15 hours per month for 20-30 years and it’s clamped to the side of your head.

I wish I had written this five years ago when I started talking about it. Then maybe I could say you heard it here first. If you read the news, perhaps you heard it from these guys first, less than a month ago:

http://economictimes.indiatimes.com/ET_Cetera/Cellphones_more_dangerous_than_cigarettes/articleshow/2945977.cms

Most people aren’t interested in thinking about this, because they don’t want to know or they don’t want to be inconvenienced by having to give up their cell phone. Also, remember the amount of money at stake for the cell phone industry. I already know what my grandchildren will be asking me in 40 years: “Grampa, what kind of insanity did everyone in those days have that made them think that clamping an intense point source of radiation to the side of their head for thousands of hours over the course of decades would not eventually kill them?” I guess most people will answer what my grandparents answered about cigarettes: “No one in those days knew it was bad for you.” I won’t.