The dangers of virtual smog

Ireland has the highest concentration of wireless hotspots in the world. At 18 per 1,000 head of population, we just about beat the UK to the number one spot. The US leads in sheer volume of these locations with 26,000. Japan, regarded as one of the most technologically-advanced countries, has actually moved beyond Wi-Fi, and now has over 30 million 3G mobile phone connections.

Carlow recently declared itself  “Ireland's first Wi-Fi town” when it launched wireless coverage for 50 per cent of businesses and 10 per cent of residencies in Carlow town, at a cost of €3m. The town will start with 11 transmitters linked to form a Metropolitian Area Network, with a much broader range than the normal hotspots. A similar project is planned for Dublin and many other towns and cities around the world.

The enthusiasm with which Ireland is embracing Wi-Fi reflects its obvious attractions, but the health effects of the technology is disputed. The BBC addressed these concerns when Panorama visited a school in Norwich, with more than 1,000 pupils. They compared the level of radiation from a typical mobile phone mast with that of Wi-Fi in the classroom. Readings taken for the programme showed the height of signal strength to be three times higher in the school classroom using Wi-Fi than the main beam of radiation intensity from a mobile phone mast. The findings are particularly significant because children's skulls are thinner and still forming, and tests have shown they absorb more radiation than adults.

In contrast to this, many scientists claim that Wi-Fi signals are safe. Wireless Fidelity uses radio waves of the same strength as microwaves, cordless phones and Bluetooth devices. These devices all create non-ionising radiation. At the levels used by microwaves, this radiation can cause heating of tissue, but the average microwave oven has 100,000 times the radiation intensity of a Wi-Fi network.

The UK's Health Protection Agency points out that a person sitting in a Wi-Fi hotspot for a year would be exposed to only the same amount of radiation as from a 20-minute mobile phone call. The World Health Organisation also says that there is no health risk from low-level, long-term exposure to Wi-Fi networks. Disconcertingly, much of this consensus is based on the fact that it is almost impossible for a scientist to prove a negative – there is no way of demonstrating that Wi-Fi has absolutely no effect on a person.