MR JAMES (Letters, September 23) says that ?no evidence of harm? is not the same as ?evidence of no harm?. True, but, if the precursor to advocating the so-called ?precautionary principles?, it amounts to saying that everyone should be locked up until he can prove that he is incapable of committing a violent crime.

The fact is that a cellphone aerial array emits about 100 watts ? one domestic electric light bulb?s worth ? of radio frequency energy. At one inch ? more than the typical distance of a teenager?s head from his cellphone?s aerial ? the field strength is 10,000 times the field strength at 100 inches (about 8 feet). If a mast array is hazardous, a cellphone must be lethal.

I have no knowledge of the Swedish research referred to by Mr Farrant, but I strongly doubt the validity of his implied conclusion from it. Meanwhile, I will state as a fact that radio frequencies, pulsed or otherwise, simply cannot pack enough energy to break chemical bonds.

Nothing in the world is risk free; it is the oxygen we breathe that, in the end, kills the survivors of all the other hazards, but that doesn?t mean that anyone will live a longer or healthier life by not breathing.

Putting things into proportion, I am more likely to be killed by a cellphone array that falls on my head after its being struck by lightning than I am to contract cancer or boil my brain by living beside one.

Roger W Mathew

West Devon Borough Councillor for Tavistock South West