How Safe Is Your Mobile
New Straits Times
July 14, 2002
How is radiation measured?
The microwave radiation emitted by mobile phones is measured as the Specific
Absorption Rate – SAR – a rough guide to how much radiation is being
absorbed by the ear and brain. The National Radiological Protection Board (NRPB)
in Britain sets the safe SAR limit at two watts per kilogram.
In some countries, mobile phone manufacturers are obliged to publish SAR
rates for each mobile phone model. These can vary from 0.30W/kg to more than
1.20W/kg.
However, Simon Best, editor of Electromagnetic Hazard and Therapy News
Report, points out that the SAR can change dramatically over a single phone
call.
“The SAR reading given by manufacturers is usually given at maximum emission
levels,” he says. “But, power levels, phone size, how you hold your phone
and the position of the antenna will all affect SAR levels and how much
radiation you absorb at any point in time.
A surge of up to 2W/kg occurs when the connection is made. How much it falls
after this, depends on the strength of your signal and battery power.
A call with a poor signal or low batteries can subject you to 100 times more
radiation than one with good reception or high batteries.
So which phones emit how much radiation and how can you limit exposure?
Below, the Daily Mail examine the most popular models, and give them a worry
rating from one to five – five being the highest anxiety.
How to reduce your exposure
* Hold the phone a few centimetres away from your ear as the connection
is made and during calls. Even one centimetre can reduce your radiation
exposure.
* The angle of handset makes a big difference, too. The vertical position
allows the phone to transmit signals most efficiently. If a phone is laid
horizontally, for example, talking while in bed, it will need to emit
significantly more radiation to work.
* Try not to obstruct the antenna, as this will cause the phone to power up.
* Enclosed spaces tend to trap and amplify radiation – if you are in a train
or car, open a window and point the phone towards it.
* Take off metal-rimmed glasses and earrings while talking, as these can
increase radiation by up to 20 per cent.