Mobile mischief or serious health risk?

Mobile mischief or serious health risk?Pete Mitchell reports on the recent speculation in the British press that mobile phones are a health hazard to their users and asks whether this is a classic example of facts getting in the way of a good story
Are mobiles scrambling our brains?” asked a famous tabloid newspaper last November, in a closely-researched, conscientious review of the health effects of RF emissions from cellphones.
Let us eschew the obvious cheap joke about the brains of tabloid readers (and writers too – the writer of that piece managed to confuse the effects of radio transceivers with those of ionising rays from x-ray machines, radio-isotopes and outer space). What is the real evidence that mobiles are a health hazard to their users, as well as to the poor devils mown down by red-light-running, phone-babbling motorists?
Most mobe-phobes will quote one or more of the following well-known horror stories at you. Laboratory mice exposed for 18 months to strong pulsed electromagnetic fields (of the type used by digital cellular phones) showed an increased incidence of lymphoma (a cancer similar to leukaemia). DNA damage (genotoxicity) was observed in the brain cells of rats exposed to RF emissions. A German study found human volunteers using a GSM cell phone for 35 minutes showed a rise in blood pressure, of about five to 10mm Hg. French scientists found higher-than-normal mortality in chick embryos exposed continuously for three weeks to mobile phone emissions. A Scandinavian study found mobile phone users reported a large number of headaches. Researchers at the Defence Evaluation and Research Agency (DERA) found that exposing slices of rat brain to low-level RF emissions reduced their activity. Earlier work at the UK’s National Radiological Protection Board (NRPB) suggested that heavy exposure to 50Hz magnetic fields causes temporary forgetfulness. Most recently, a human trial at Bristol University has suggested that intensive mobile phone use actually speeds up your reaction times. No-one knows why, or whether that is good or bad for you.
So there you are. Mobile phones make you forget things, cause headaches, raise your blood pressure, damage your DNA, give you cancer, and shorten your life span generally – but do make you quicker on the draw.
Not, in short, the latest health-promoting fashion accessory on sale at the gym, unless taken with a neckful of magnetic amulets prescribed by your personal aromatherapist.
The court cases have started already, even in England (in the USA, they started the same day mobiles were launched, or maybe the day before). Last year, one vocal mobe-phobe, Roger Coghill, tried to get all sets labelled as hazardous. His case was dismissed in the UK, but the European Parliament is still considering the idea. And a former engineer is suing his ex-employer BT after he began getting headaches, memory lapses and impaired hearing. His job was driving round the UK testing mobile phone coverage. There will be many more cases like his.
Why, then, has no-one stopped this fearful scourge – this modern-day equivalent of the Black Death?
Because none of this medical research is very convincing. For one thing, the reported symptoms are rather too broad. Almost anyone is going to suffer from at least one of them, especially if they have read about the risks of mobiles in a newspaper.
It’s all a bit like the silicone breast implant scare: once a craze like that gets going, anybody who feels unwell can blame it on something they bought recently.
Take headaches. How do you prove that mobile phones cause headaches? You compare the incidence of headaches in two groups of people who are similar in every way except one: group A uses mobiles while group B (the control group) doesn’t. Is the difference more than chance might predict? The groups have to be very large to eliminate a chance effect – headaches have lots of causes and everybody gets them. And there is always the problem of bias:was the researcher keener to find headaches in their group A than in group B? After all, if no difference at all is found, the researcher probably won’t get published. And maybe the subjects recruited knew the researcher was looking for a link to mobile phones, and adjusted their reports to match. Unlikely? It happens all the time.
Our Scandinavian headache researchers (Mild et al) solved the problem simply by not bothering with a control group. Apparently the place is so full of mobiles, they couldn’t find enough people that didn’t use them. So all we have there are anecdotal reports of headaches among mobile users. Big deal.
So the acclaimed ‘proof’ melts away on closer examination; but that didn’t stop the newspapers splashing on it. Would they have done so if Mild et al had found nothing? Er, no. ‘Mobile Phones Fairly Safe Shock’ sells no papers.
One can pick similar holes in nearly all the reports, says cancer expert Professor John Moulder of Wisconsin Medical College. The blood pressure study – published in The Lancet, no less – was, he says “small and not blinded”. That is, everyone knew which subjects were using mobile phones and so could unconsciously fiddle the results. Anyway, he says, such a small increase in blood pressure has no known health consequences.
What about the dead chicks? In that experiment, exposure was for 24 hours a day at 2W levels, compared to the usual 0.5W. That level of power could have produced tissue heating that would damage the embryos, says Moulder. And, according to the UK’s NRPB, if there is a health risk to humans, it’s nothing to do with heat: “The output power from a mobile is too low to cause adverse effects due to heating.”
The mouse lymphoma result is the most interesting, says Moulder – though even in that, the radiation doses were well above mobile phone handset levels. And quite a few other reports elsewhere have indicated that RF produces no extra tumours, so it could have been a fluke. The same goes for the DNA mutation experiments. As all grant-funded researchers say in these circumstances, “more research is needed”.
Tom Wills-Sandford of the Federation of the Electronics Industry might be expected to agree, and he does. “The media do not report findings of no substantive health risk, but they do like to report health-risk stories”. He also points to the merchandisers of phone shielding devices as a source of fear and uncertainty. Some of these devices would stop the phones working at all if they lived up to their promotion, he says. Mind you, quite a few of them work by strengthening your own bio-energy, so the sales patter is bound to be just a tiny bit optimistic.


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