Wireless laptops 'may harm children'

Youngsters should be monitored as public concern continues over emissions from wi-fi networks, Professor Lawrie Challis, who heads the committee on mobile phone safety research, told The Daily Telegraph.

Until more research is carried out, children should keep a safe distance from the embedded antennas on wi-fi enabled laptops, he said.

"With a desktop computer, the transmitter will be in the tower," he told the newspaper.

"This might be perhaps 20cms from your leg and the exposure would then be around one per cent of that from a mobile phone."

But if a laptop was placed straight on the lap when using wi-fi, people could be around 2cm from the transmitter, and receiving comparable exposure to that from a mobile phone, he said.

He added: "Since we advise that children should be discouraged from using mobile phones, we should also discourage children from placing their laptop on their lap when they are using wi-fi."

Prof Challis said the potential risk might be greater for children who were more sensitive than adults to some dangers, like UV radiation.

Jeff Hands, professor of imaging physics at Imperial College London, said: "If we are talking about health issues linked to localised heating of tissue then these will be insignificant at the power levels we are talking about here."

Alasdair Philips, director of consumer group Powerwatch,told the Telegraph it was not the heating of tissue that was the problem but the interference wi-fi radiation could cause to the electrical signals within a person's brain and nervous system.