Tech Lab

There's no easy escape from cellphone risks

By Hiawatha Bray
Globe Staff / June 2, 2011

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Forget whether your cellphone technology is 3G or 4G. It’s time to start worrying about 2B.

That’s the World Health Organization’s official designation for chemicals or other agents that may cause cancer in humans. And the radio waves streaming from the world’s 5 billion cellphones have just been added to the WHO’s 2B list.

The ranking means that using your cellphone may pose about as much cancer risk as eating pickled vegetables or drinking coffee, both substances that are also on the list. Coffee’s potential as a carcinogen has not hurt Starbucks’ revenues. So don’t expect to see pay phones sprouting on street corners as panicked consumers discard their iPhones and BlackBerries.

Still, the threat of brain tumors — no matter how slight — is troubling to WHO scientists. Americans average about 20 minutes of cellphone talk time per day, according to data from CTIA, the cellular industry’s trade association.

That doesn’t sound like a lot. But researchers were alarmed by a study that found an increased incidence of brain tumors in people who used their cellphones for an average of 30 minutes per day.

What to do? You can find lots of advice for protecting yourself, but some of it is useless. For instance, some companies sell shielding devices that purport to protect users from the radio waves. But the Federal Communications Commission says they don’t work. The point of a cellphone is to transmit radio signals. Any shield that completely blocked them would make the phone useless.

The Environmental Working Group, a lobbying outfit in Washington, D.C., recommends buying phones that transmit at a lower power level. All cellphones sold in the United States are tested to ensure they meet a federally mandated power limit. At websites such as, you can look up the maximum output ratings for many phone models.

But the FCC warns that shopping for a lower-powered phone may not help. Phones rarely broadcast at peak power. Average power output, which isn’t rated, is much more important. A phone’s peak power rating, for example, might be fairly low, but its average output could be relatively high, making it a riskier choice.

For a more practical defense, make like a teenager, and text instead of talking. Sending SMS or e-mail messages keeps the phone well away from your skull. The farther your brain is from the phone, the lower the risk of brain tumors.

If you must talk, most handsets have a speakerphone feature to let you converse at a distance. I often use it because I’m too lazy to hold the phone. Now I’ve got a better reason.

Bluetooth wireless headsets offer an extra measure of safety because they use a low-powered radio that will feed far less radiation into the brain. Then again, some Bluetooth fans wear the little earpieces like digital jewelry, clamping them to their ears for hours at a time —much longer than most people hold a phone to their ears. Nobody knows of any hazards posed by long-term exposure to Bluetooth signals, but why take chances? Consider removing the earpiece or switching it off when it’s not in use.

Or consider a wired headset. They are a bit more cumbersome but will reduce exposure even more. Of course, wired headsets still radiate a weak magnetic field — enough to worry some people. Some engineers recommend attaching a ferrite bead, a cheap clip-on device that filters out this radiation.

Even an extra inch of distance can help. The safety manual for my BlackBerry Bold phone suggests keeping it at least 0.98 inches from the body at all times.

Any closer, and users could be exposed to an excessive level of radio waves, according to the manual, which notes “the long term effects of exceeding RF (radio frequency) exposure standards might present a risk of serious harm.’’

Luckily, I carry the phone on my hip, in a holster which keeps it the required distance from my body. I’ve mocked my wife for losing her Android smartphone in her purse, but carrying it well away from the body is the safest way to go.

Still, the risk from cellphones remains modest and tentative. And these gadgets, now used by two-thirds of the human race, have surely saved far more lives than they’ve harmed.

Once a luxury, cellphones are now indispensable. They can have mine when I’m dead — but preferably not from a brain tumor.

Hiawatha Bray can be reached at