Teachers in Britain are concerned about possible health risks from wireless computer networks in schools. The Professional Association of Teachers (PAT) teachers' union is writing to the education secretary for a clarification on wi-fi safety. "There's a concern the potential health risk of this technology hasn't been investigated fully," said the union's general secretary, Philip Parkin. He wants Education Secretary Alan Johnston to ask for a "full scientific investigation into the effects of wi-fi networks in schools". "I am concerned that so many wireless networks are being installed in schools and colleges without any understanding of the possible long-term consequences. I am not saying there is a danger, but I have enough concern to ask for it to be investigated." The union highlights the case of Michael Bevington, a classics teacher at Stowe school in Buckinghamshire. Mr Bevington "had never had any problems before the wi-fi. When it was put into his classroom he suffered nausea, blinding headaches and a lack of concentration. When the school removed the wi-fi his condition improved". The Health Protection Agency says "wi-fi devices are of very low power, much lower than mobile phones". But at the same time, the agency does not offer a clear guarantee of its safety. The need for greater research into health hazards from such technology is reflected in the minutes of an HPA meeting last month - where on the issue of "electrosensitivity" it was said that "scientific investigations conducted so far very seldom give clear answers". A two-day meeting of experts on electrosensitivity, with a "political and scientific remit", was proposed by the HPA for early next year. (Source: BBC)