Concern about the health consequences of steady exposure to radiation emanating from WiFi networks just won't go away. A few months ago the president of a small Canadian college banned WiFi from campus owing to health concerns, and there is an increasing body of evidence to suggest that certain people are sensitive to the emissions from wireless APs and other electromagnetic devices and, when spending time in a WiFi-saturated environment, tend to suffer from headaches, fatigue, irritability and lack of concentration.

"There seems to be a small proportion of people who react badly to wireless networks," said Alasdair Philips, chairman of independent watchdog Powerwatch and a member of the U.K. government's Stakeholder Advisory Group on extremely low frequency electromagnetic fields. "For example, I've seen several doctors and dentists who have put wireless LANs into their surgeries and then had complaints from staff who can feel something in their head or can't concentrate properly. But when they've taken out WiFi and put cable in, the problem has disappeared."

Philips says there is a need for more rigorous studies of the problem, but he also says that electrosensitivity affects a significant number of people. "A lot of people are reporting the problem and awareness of it is growing. Some studies estimate only one-in-10,000 people is electrosensitive; others suggest it's as high as 30-in-100. In our opinion, it affects about two and three percent of the population to some degree," he said.

In March, the U.K. government's Health Protection Agency set up a group to help develop precautionary advice for the general public regarding exposure to electromagnetic fields, but Philips says we are at least five years away from more formal regulations being introduced. Until that time, Philips offers this advice to businesses and organizations with WiFi networks: "If you've already got [a WiFi network in the office], be aware of the symptoms some of your staff may be suffering--things like headaches, fatigue, irritability and lack of concentration," he said. "If you see increasing numbers of those symptoms in particular staff, it might be worth putting those staff in a different part of the building with a wired network."

For more on the health effects of WiFi:
- see this Sci-Tech Today report