Why I'm not worried about my cell phone causing brain cancer

The World Health Organization's cancer "risk" is indistinguishable from chance

By Shawn Lawrence Otto | Jun 01, 2011 | Comments (8)

Today the big news is a release by the World Health Organization about a "possible" link between brain cancer and cell phone use.  They class the use in the same risk category as - get this - eating pickled vegetables or drinking coffee.  Seriously?

My step mom died of glioblastoma multiforme.  It was a particularly horrible way to go.  But I'm not worried about my brain, my wife's brain, or my son's brain, at least from cell phone use.  Why?  Physics.

Physics explains why broad epidemiological studies have shown no measurable links between cell phone use and an increased incidence of brain cancer - and the Ntional Cancer Institute has shown no appreciable increase in brain cancer rates since 1987, despite a massive surge in cell phone use.  It's because the microwaves used in cell phone transmissions do not have enough energy to break the chemical bonds of DNA, which is how cell mutations occur and cause cancer. The WHO study is, well, WHOoey, and they have hurt their own credibility.

What the WHO study cannot say

It is true that the studies done to date cannot rule a link out, but that is because that's the way science works.  Because we cannot observe the whole universe at once, science is a game of making statements about the relative probability that something is true.  That's why it uses statistics.  And from all the studies done so far, statistically, the "link" is indistinguishable from chance - which is what the footnote in the WHO press relase admits (!).  So sure, it's possible.  But that is not a scientific statement.

Why microwaves don't cause cancer

Here's a 1-page physics lesson for all you WHO doctors out there.  Light and other parts of the electromagnetic spectrum, including microwaves, radio waves, infrared waves, and ultraviolet light waves, are all forms of radiation. A single unit of radiation is called a photon. A photon can be thought of either as a particle, or as a wave.  A century ago, Albert Einstein showed that the energy (E) of a photon can be calculated as Planck's constant (h) times the frequency (v) of its wave form, or E=hv. This formula was set out in one of his early papers, and was one of the reasons for which he won the 1921 Nobel Prize in Physics.

Photons with low frequencies are at the red end of the spectrum. They include radio photons, whose waves can be as long as a football field and thus fly past us with low frequency and low energy. Microwaves are slightly stronger, followed by infrared radiation and then visible light waves. Waves at the high end of the spectrum fly past us at much faster frequencies (and thus have more energy) and appear more blue. This part of the spectrum includes ultraviolet light, followed by the even more energetic x-rays, followed by gamma rays, whose waves can be shorter than the diameter of the nucleus of an atom and thus very high frequency and very highly energetic. 

Image courtesy of NASA

Microwaves are slightly more energetic than radio waves, but far less energetic than even the infrared radiation that our own skin gives off (!), which is how we can be seen by someone wearing infrared night vision goggles.

Both visible light and microwaves can be used to cook food and heat up your coffee by concentrating them in very large amounts, such as in a solar oven or a microwave oven. So can infrared. The concentrated waves excite the molecules in a way that increases their vibration, and the friction that produces increases their temperature, but they still don’t have anywhere near enough energy to break chemical bonds. If they did, the food would turn into goop. Microwaves are much weaker than visible light, though, so it takes a lot more of them to make an oven work than it does to make a solar oven work, which is why microwave ovens are such electricity hogs.

What radiation does cause cancer

It’s not until you travel into the red end of the visible light photons, then on to the yellow emitted by incandescent bulbs, then to the blue that illuminates many fluorescent bulbs, and then on past the visible spectrum into ultraviolet light that you get photons that have a high enough frequency and thus enough energy to break DNA bonds. These photons have about a million times more energy than microwave photons, enough that they can act like cue balls and knock electrons out of atoms, ionizing the atoms and changing their chemical nature. This is what Einstein’s 1905 paper showed. Just imagine the force of a wave the length of a football field being concentrated into a wave the length of a molecule and then flashing past you over and over and over, and you can get a sense of the vast difference in the power of the two. That is what can break the bond between two carbon atoms, damaging DNA and causing cancer. But these ultraviolet photons still don’t have enough energy to penetrate us very deeply, so they can only give us skin cancer.

Electromagnetic radiation above this level grows increasingly dangerous. X-rays are sometimes stopped by our skin, but if we are bombarded by enough of them they have enough energy to penetrate through us, a few of them being absorbed by skin and muscle, many more by our bones, which are denser, and many shooting that cue ball of a photon clear through us, which is why we can use them to make images of the inside of our bodies. X-rays can and do cause cancer, but our bodies can almost always stop it if the exposure is low enough. Gamma rays are so energetic that they can penetrate us, kill cells, and cause cancer very easily, and in high exposures they cause radiation poisoning, which kills much more quickly by damaging our bone marrow and gastrointestinal tract.

The cell phone scare to really worry about

Physicists like Bob Park try constantly to point this out and show that, like water, not all radiation is bad for us. Some is even necessary for life. Tsunamis kill, but streams nourish—the difference is in the amount and energy of the water. 

So while it is possible that some mechanism we don't understand could be causing brain cancer at levels that are currently indistinguishable from chance, I for one am far more worried about some kid texting and crashing into me than I am about my own phone killing me with cancer.

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