Britain's top health protection watchdog is pressing for a formal investigation into the hazards of using wireless communication networks in schools amid mounting concern that they may be damaging children's health.

        Sir William Stewart, the chairman of the Health Protection Agency, wants pupils to be monitored for ill effects from the networks - known as Wi-Fi - which emit radiation and are installed in classrooms across the nation.

        Sir William - who is a former chief scientific adviser of the Government, and has chaired two official inquiries into the hazards of mobile phones - is adding his weight to growing pressure for a similar examination of Wi-Fi, which some scientists fear could cause cancer and premature senility.

        Wi-Fi - described by the Department of Education and Skills as a "magical" system that means computers do not have to be connected to telephone lines - is rapidly being taken up in schools, with estimates that more than half of primary schools - and four-fifths of secondary schools - have installed it.

        But several European provincial governments have already taken action to ban, or limit, its use in the classroom, and Stowe School has partially removed it after a teacher became ill.

        This week the Professional Association of Teachers, which represents 35,000 staff across the country, will write to Alan Johnson, Secretary of State for Education, to demand an official inquiry. Virtually no studies have been carried out into Wi-Fi's effects on pupils, but it gives off radiation similar to emissions from mobile phones and phone masts.

        Recent research has linked radiation from mobiles to cancer and to brain damage. And many studies have found disturbing symptoms in people near masts.

        The Government insists Wi-Fi is safe, but a Panorama investigation shows that radio frequency radiation levels in some schools are up to three times the level found in the main beam of intensity from mobile phone masts. There have been no studies on the health effects of Wi-Fi equipment, but thousands of mobile phones and masts. The radiation Wi-Fi emits is similar to that from mobile phone masts. It is an unavoidable by-product of going wireless. Entire cities have become what are known as wireless hotspots.