A prominent Scots scientist has called for a review of the health effects of wireless computer networks in schools following a BBC investigation.

According to the Panorama programme, the computer systems can give off greater levels of signal radiation than a typical mobile phone mast.

The chairman of the Health Protection Agency, Sir William Stewart - a former president of the Royal Society of Edinburgh - calls for a review in the programme. Sir William told Panorama: "I believe that there is a need for a review of the wifi and other areas. I think it's timely for it to be done now."

Government advice recommends masts are not sited near schools without consultation as children are thought to be more vulnerable to radio frequency radiation emissions than adults, the series states.

But when Panorama visited a comprehensive school in Norwich and measured the radiation signal strength from a classroom wifi laptop, they found its peak was three times greater then the peak signal strength from a mast.

The Panorama report, to be shown tonight on BBC1, will say 70% of secondary schools in the UK already have wifi and nearly 50% of all primary schools do. The programme contacted nearly 50 of these schools and claimed only one had been alerted that there might be possible health risks, while some had been told there was no risk.

The government states there is no health risk from wifi and cites the World Health Organisation's view that there are "no adverse health effects from low level, long-term exposure," the programme reported. The government relies on the data supplied by ICNIRP, an international group of scientists, for radiation safety limits.

But Panorama states the body does not take into account the biological effects of radio frequency radiation and bases exposure limits on a thermal effect.

Professor Henry Lai, a biologist from Washington University, reviewed all the experiments on mobile phones. He found health effects at similar levels of radiation to wifi in some of the studies. He said: "I think it's about 50-50; 50% found an effect and 50% did not find an effect at all"

"I think it's irresponsible to just set standards using a thermal standard.

"If you set it just based on a thermal effect you are neglecting a large amount of data."