CONCERN about Orange?s new replacement mast at the top of town has led me to investigate the risk of health effects on Tavistock?s residents. The mast looks scary, but my checks suggest we need not worry about them.

The sort of radiation mobile phone masts emit is called microwave radiation. We are surrounded by such radiation from many sources, including TV and VHF radio, and we come to no harm from it. At the frequencies used by microwave ovens, it shakes up water molecules and causes the water to warm up. It has no other ill effects. The frequencies of this radiation are nothing like that of ultra-violet or ionising radiation.

We are considering the effect of heat on people. Well, we all know the intense heat inside a microwave oven, which works at a similar frequency. Some microwaves leak out but screening prevents nearly all of them from getting out.

Similar radio waves are emitted by mobile phones. Most of us have a mobile and do not see it as dangerous ? and indeed it is not. Its field strength is so very small. It sends radio waves to a mast, which sends them elsewhere. The power needed to get a signal from a cell-phone to a mast is of the same order as that needed to forward the signal onwards. All of it is subject to what the experts call ?the inverse square law?. This says the intensity of a field of radiation is inversely proportional to the square of the distance from the source. In other words if it?s twice as far away, there is only a quarter of the power.

It follows that it is safer for us to text messages than to talk for long periods with the phone to our ear and thus much closer to our brains. In the same way, when the mast antennae emit radio waves, the intensity of the waves? exposure diminishes very rapidly. It has very much less effect on a person standing a yard or two away than on someone whose ear is an inch away from a phone. Now I understand the antennae on the masts stand forty feet high or more, so I cannot see the possibility of any risk from them.

I do not like these masts ? Dartmoor?s skyline is spoiled by such ugliness already. but I am satisfied they do not cause harm other than to impair the beauty of our countryside.

Dick Eberlie

Member for Tavistock

West Devon Borough Council