It's not a good idea, says a scientist who headed up a British government-commissioned probe into the safety of cell phones. Sir William Stewart of Tayside University in Scotland says children should not use mobile phones until more is known about any effect they may have on still-developing skulls and nervous systems. Stewart at the same time noted that "no firm evidence" has been found linking cell phones to any risk to the health of the general population. He estimates it could take a decade for evidence of any risks to emerge and if harmful effects are found, they are more likely to be seen in children because their bodies are still developing. "In line with our precautionary approach at this time we believe the widespread use of mobile phones by children for non-essential calls should be discouraged," cautioned Stewart, in a BBC radio interview.

The report by Stewart and other scientists working on the inquiry could be a blow to the cell phone industry, which has sought to tap the vast youth market. Stewart says there is some "preliminary evidence" that emissions from mobile phones can cause subtle biological reactions, such as changes in response times. "That does not mean that these effects lead to disease," explains Stewart. "But this is a new technology and we are recommending...that a precautionary approach be adopted until new information is available." Children have thinner skulls, smaller heads, and still-developing nervous systems, all factors which can make them more vulnerable to any adverse effects from the phones, according to Stewart.

The British inquiry committee was established last year to investigate concerns that radiation from mobile phones might be able to trigger cancer, memory loss and Alzheimer's disease. Stewart says the public ought to have more information when they buy mobiles, and there should be better planning about the location of mobile phone antennas. Will Stewart continue to use cell phones, now that he's spent some time studying the increasingly popular devices? He says yes, but he will not recommend that his grandchildren do the same. A source close to the inquiry Wednesday told Reuters that the scientists were worried by "odd findings." "One odd finding came up when we looked at microwave radiation on nematode worms. That showed odd changes to the protein structure," said the source. "It was a kind of heat shock on the protein. You know, slightly cooked."