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In a culture where people cradle their cellphones next to their heads with the same constancy and affection that toddlers hold their security blankets, it was unsettling last month when a study published in the Journal of the American Medical Association indicated doing so could alter brain activity.
The report said it is unclear whether the changes in the brain – an increase in glucose metabolism after using the phone for less than an hour – have any negative health or behavioural effects. But is has many people wondering what they can do to protect themselves.
In light of the findings, Dr. Nora Volkow, the lead investigator of the study and director of the National Institutes of Health advises users to keep cellphones at a distance by putting them on speaker mode or using a wired headset whenever possible.
The next best option is a wireless Bluetooth headset or earpiece but also also emit radiation, albeit at far lower levels.
If a headset isn’t feasible, holding your phone just slightly away from your ear can make a big difference because the power or intensity of radiation diminishes dramatically with distance.
Every millimetre counts,” said Louis Slesin, editor of Microwave News, an online newsletter covering health and safety issues related to exposure to electromagnetic radiation.
So crushing your cellphone into your ear to hear better in a crowded bar is probably a bad idea,. Go outside if you have to take or make a call. And to prevent further radiation exposure you might not want to put your cellphone in your breast or pants pocket either because similarly puts it right up against your body.
Carry it in a purse or briefcase or get a non-metallic belt clip that orients it away from your body.
Real or imagined?
Some studies have suggested a link between cellphone use and cancer, lower bone density and infertility in men. But these studies conflict with others that show no effect at all.
The phone used in Volkow’s study was a Samsung Knack, model SCH-U310, a flip-phone that was in wide use when she began planning her experiments two had half years ago. But today’s ubiquitous smartphones emit even more radiation as they transmit, more, and more complex, data.
You can get an idea of the relative amounts of radiation various cellphone models emit by looking at their SAR, or Specific Absorption Rate. This number indicates how much radiation is absorbed by the body when using the handset at maximum power.
A cellphone cannot be sold in the United States unless a FCC-approved laboratory says its SAR is below 1.6 watts per kilogram. In Europe, the maximum is 2 watts per kilogram.
The SAR number is not displayed when you compare cellphone at your local store, and trying to find it in the fine print of you user manual is an exercise in frustration.
The FCC maintains that SAR values `do not provide sufficient information` to reliably compare cell phone radiation emissions because certain phones might rarely operate at maximum power.
Still, the Environmental Working Group, a non-profit organization, has a comprehensive list of the SAR values for most cellphones available from major carriers on its website. (For instance, the Apple iPhone 4 is listed at 1.17 watts per kilogram, the Motorola Droid at 1.5 and the LG Quantum at 0.35.)
Best ways to use a phone
But more important than looking for low-SAR phone is how you use it. Many cellphones emit the most radiation when they initially establish contact with the cell tower, when they make their `digital handshake.` So to reduce exposure it’s best to wait until after your call has been connected to put your cellphone next to your ear.
During ensuing conversation, it’s advisable to tilt the phone away from your ear when you are talking and only bring it in close to your ear when you are listening.
The bit of teeter-totter works because the emission of radiation is significantly less when a cellphone is receiving signals than when it is transmitting. Moreover, your cellphone emits less when you are stationary because when you are moving rapidly – say, in a car or train – it must be repeatedly issue little bursts of radiation to make digital handshakes with different towers as it moves in and out of range. (More cause to hang up when you buckle up.)
Perils of poor reception
Any situation where your cellphone has a weak signal indicates it has to work harder and thus will emit more radiation. Fewer bars means more radiation. Inside buildings and elevators or in rural areas – these are not good places to make a call if you’re trying to reduce your exposure to radiation.
Of course, parents using their iPhones to pacify cranky kids might want to reconsider rattles. Children’s developing brains and tissues are thought to be most vulnerable to cellphone radiation. Health authorities in Britain, France, Germany and Russia have all issued warning against allowing small children to use cellphone for extended periods, it at all.
There are cellphone attachments that purport to shield users from radiation and most are `hoaxes`. Beware of pendants that sellers claim snatch radiation the air.
Pong Research offers a cellphone case for iPhones and Blackberrys that is says has been shown by an FCC-approved resting lab to redirect radiation from the phone’s antenna away from the head.
While manufacturer says it reduces radiation more than 60%, some electrical engineering experts question whether the case may have the opposite effect at orientations where your head is in the way of the cell tower because your phone may have to increase is transmission strength somewhat to compensate for the redirected signal.
The company disputes this. Nevertheless, the net affect of using the device throughout the course of the day may be a reduction in total exposure.
Texting, instead of talking, might be safer. That is, if you don’t rest your cellphone against your body while typing out your message.
(NYT)
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