Use of wireless internet in schools could cause cancer or make pupils sterile later in life, warn UK teachers.
Government investigation has been called for into the biological and thermal effects of "wi-fi" networks by the Association of Teachers and Lecturers (ATL).
However, health experts said there was no evidence the technology had any detrimental effect, reports The Scotsman.
Colin Kenney, of Cookstown High School, in Northern Ireland, who called for the investigation, said that international experts had called for caution when using wi-fi technology.
He asked: "Have we the moral right to ignore the warnings - simply for access to a few more computers - and are our pupils going to thank us in the years to come if they have become sterile or suffer from cancer brought on by, or exacerbated by, exposure to wi-fi?
"Perhaps they will just be eternally grateful that we enabled them to finish their presentation for geography."
Kenney has demanded long-term safety studies until it could be proved that the technology was safe.
He added: "As teachers, we may have to wait a little longer for the new ICT (information and communication technology) suite to become available, but at least we will be safeguarding health."
However, Dr Michael Clark, scientific spokesman for the Health Protection Agency (HPA) said: "On the basis of research so far, there is no hard evidence of any ill health effects from wi-fi.
"The signals are very low, in fact there is more wattage coming from the battery."