The UK's Health Protection Agency, which has responsibility for dealing with radiation safety issues, has said statements attributed to its chairman, Sir William Stewart, in an article in The Independent on Sunday were not his and that he was not prepared to condemn Wi-Fi, even though he was being pressed by lobbyists to do so.

The article in question, Wi-Fi: Children at risk from “electronic smog”, published last Sunday, said that Stewart wanted pupils “to be monitored for ill effects from the networks - known as Wi-Fi - which emit radiation and are being installed in classrooms across the nation”.

The statement on the Radiation page of the HPA's web site says: "Wi-Fi devices are of very low power, much lower than mobile phones. The HPA and Sir William have always pressed for more research into these new technologies. The only firm precautionary advice issued by the HPA is about children's use of mobile phones."

The Professional Association of Teachers (PAT) general secretary Philip Parkin has released a statement saying: "I am writing to the Education Secretary to ask for a full scientific investigation into the effects of Wi-Fi networks in schools."

Parkin argues that profits from wireless kit sales means that vendors maybe are not doing enough to research physical effects of wireless radiation on children. "I am not saying there is a danger, but I have enough concern to ask for it to be investigated. There are huge commercial pressures which may be why there has not yet been any significant action," Parkn said.