I'm on the train, frying my brain

BRITAIN
Mobile phones and risk

Jan 13th 2005
From The Economist print edition

Mobile phones still seem to be safe, but nobody wants to hear that

“THERE is as yet no hard evidence of adverse health effects on the general public,” Sir William Stewart, chairman of the National Radiological Protection Board, an organisation that sounds as though it belongs in a 1960s B-movie. “But because of the current uncertainties we recommend a continued precautionary approach to the use of mobile-phone technologies.” To a Popper-reading scientist, that's a little like saying: although there's no evidence that the sky is going to fall in, you should hide under your desk anyway.

Since ministers flatly denied there was any danger to people from mad-cow disease, Britain's government and press have been jumpy about public health. That helps explain Sir William's attitude, the scary headlines it generated and a decision by Communic8, a handset-maker, to withdraw a phone aimed at children.

One possible danger identified by the report concerns mobiles with a high specific energy absorption rate (SAR), a measure of the energy the head absorbs while the user is talking.

Different phones have different SAR values, and the report recommends choosing a phone with a low one. But the SAR also depends on things like how close a user is to a mobile phone mast (the further the mast is, the more your brain gets cooked) and how garrulous the user is (people who listen rather than talk will have cooler skulls). One way to reduce the SAR is to have lots of masts. But people tend to think they are dangerous too, so that would be unpopular.

Even when a phone does heat up its user's head, it is not clear what is particularly bad about that. Adam Burgess, a sociologist at Kent University who has written about mobile phones and public fears, has pointed out that humans survive warm baths. A Swedish study has shown an increase in acoustic neuromas (a non-malignant tumour of the nerve that supplies the ear) in people who have used mobiles for ten years. But critics point out that the study has not been replicated, and that old mobiles might have had different effects from current ones. Even so, the nervous will be relieved to know that a hands-free kit reduces the SAR by about half.

Anyone who wants a definitive answer will probably have to wait a long time. Concerns about the public-health effects of overhead power lines were first outlined in a paper in 1979. Some people are still not satisfied that they are safe.

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