In Wi-Fi and WiMAX wireless systems, computers network and access the Internet using microwave-frequency electromagnetic signals (similar to those used by mobile phones) rather than wires.

If you have Wi-Fi in your office or computer room, you are being exposed to microwave radiation all of the time the computer is switched on, but especially when you transmit or download data. Although the signals are much weaker than those emitted by, say, cordless telephones, no safety research has been carried out so, by going Wi Fi, you are signing up to a global health experiment.

Your choice in this matter may be short-lived. British Telecom, for instance, has signed deals with twelve local councils to fit Wi-Fi antenna to walls and street lamps to create zones where people can get wire-less access to the net. When this occurs, people living in those towns will be continuously exposed to Wi-Fi whether they like it or not. BT aims to have the first six public zones operating by early 2007.

And if that wasn’t bad enough, Wi-Fi zones nationwide will soon be replaced by WiMax zones where, as the name suggests, the signals will likely be stronger. This has already begun in parts of London and in some other large towns.

Security
Security is another issue. Once Wi-Fi is operating in a house or office it is perfectly possible for someone with a WiFi laptop to park outside, connect into your system and download files from your computer(s). They could also use your internet link to download child pornography from the Internet. As the owner of the link, you would be the one who got the visit by the police.
There are ways to stop this happening but they can be complex to set up.

In the UK Wi-Fi antennae do not currently require planning permission, so no-one actually knows how many have already been installed or where. They emit radiation levels similar to the mobile phone microcell units often mounted (and sometimes disguised as burglar alarms) on the walls of buildings. A further worry is that the UK’s Office of Communications (Ofcom) is considering increasing the permitted signal strengths of these antennae.

‘Homeplugs’
If you have more than one computer in your house or office and like the idea of networking them (linking them together so that you can easily share documents, software or computer games), there are three ways currently available:

• purchasing networking software and running computer-grade cables between the computers you wish to link (potentially laborious and messy)

• installing wireless (Wi-Fi) software and equipment (which exposes you to microwave radiation when turned on, and particularly when something is being transmitted or downloaded - not recommended by Powerwatch UK)

• installing ‘HomePlugs’, which plug into your ordinary three- pin electricity wall sockets and use the electrical wiring of your house or office to exchange data. Powerwatch UK use ‘HomePlugs’ and advise that they emit “vanishingly small” levels of shortwave signals, so are almost certainly safe to use

Using HomePlugs in combination with a suitable modem/router, all of the computers in your house can also share the same broadband telephone line. Low and high speed HomePlugs are available from Dixon’s and several websites (e.g. www.homeplugshop.co.uk).