Thursday, November 23, 2006

Wi-fi fears

'Health fears lead schools to dismantle wireless networks,' reports the Times (London) this week. Parents and teachers have been requesting that wi-fi networks connecting computers in classrooms be removed because of fears that the radiation from them could be affecting health. 'We listened to the parentsí views and they were obviously very concerned. We also did a lot of research. The authorities say itís safe, but there have been no long-term studies to prove this,' said Tim Cannell, headmaster of a preparatory school in Sussex. Nor is this concern unique: in January this year, for example, the president of Lakehead University in Canada refused to allow a campus wireless network for the same reasons. Fred Gilbert said it was 'a matter of taking precautions and providing an environment that doesnít have a potential risk'.

There is no evidence that the tiny amounts of radiation involved in wi-fi networks - measured in milliwatts - could have any biological effect. Concerns about wireless networking are obviously a spin-off from other concerns about mobile phones and power lines - but, if anything, the concern is even more misplaced.

As numerous studies have shown, there is basically no evidence that having a mobile phone right next to your head will cause any harm. But wireless cards and routers aren't even placed right next to our heads. Not only is the output from a wireless network card or a router tiny to start with but the intensity of the output weakens dramatically as you move away from it, so having a wi-fi router some distance from you is even less likely to be harmful.

You can see this effect with a 40-watt light bulb. Put your eye close to it and the light is likely to feel painfully bright. As that same light spreads out, however, it becomes much weaker. On the walls of the room, the light from a 40-watt bulb will be pretty feeble. So, even being a few feet from a source of energy makes a huge difference to the power you receive from it - and the same thing applies to wi-fi equipment in classrooms.

This concern has got nothing to do with any evidence that there might be harm caused by such devices. The headmaster's statement about the lack of long-term studies is obviously true - wi-fi is new technology. But we don't need epidemiology to tell us that tiny amounts of energy are harmless.

Rather, the notion of invisible forces silently damaging us - or worse, our vulnerable children - is a powerful metaphor for the way that modern society has increasingly left us feeling isolated and open to attack. Unlike the microwave radiation, this health scare, like so many others in recent times, is all in the head.

Health fears lead schools to dismantle wireless networks, The Times, London, 20 November 2006

Health concerns limit wireless Internet at Lakehead University, IT Business (Canada), 23 January 2006