Dozens of scientists and much of the mobile phone industry may wonder why Professor Lawrie Challis is planning an expensive study of 200,000 mobile users to establish as definitively as possible whether handsets pose an increased risk of cancer. Many people may actively wish he would accept the reassuring findings of the best research to date and drop the matter. Even so, the imminent deal to fund the British study, disclosed in The Times today, is welcome.

This is not because there is any compelling evidence of a link between mobile phone use and serious disease. On the contrary, there is no such evidence — yet. It is because the devices have assumed such prominence in our lives so quickly that it is too soon to dismiss entirely the possibility of such a link. And their effects in terms of quality of life and productivity are so broadly beneficial that Government, science and industry must seek the soundest possible basis for their continued use.

Since 2000, the number of mobile phones in use by adults in Britain has doubled to 50 million, and the number being used by children aged 5 to 9 has risen by a factor of five. Those naturally inclined to suspect any major technological advance of coming at a human cost have heard (and issued) enough alarmist warnings to induce hands-free paranoia in the most ardent technophile. Most of these warnings are anecdotal at best. So far they have been comprehensively discredited by serious scientific surveys, notably a large-scale Danish study published last month. This matched the mobile phone records of 420,000 users to the Danish Cancer Registry and found no correlation between phone usage and incidence of cancer.

Yet there are three specific grounds for continuing with similarly rigorous research. The first is an earlier Danish study of 2005 that did appear to find a marginally increased risk of certain types of brain tumour among long-term mobile users. Professor Challis, who is chairman of the government-sponsored mobile telecommunications health research programme, calls this a “hint”.

Secondly, mass mobile phone use is still relatively recent. Most major causes of cancer discovered in the past century, from tobacco smoke and nuclear radiation to overexposure to sunlight, take more than ten years to have their full effects demonstrated. There is no intrinsic reason to suppose that the radiation emitted by mobile handsets is harmful. Nonetheless, their widespread usage represents the first time that radiation sources of this type have been used for prolonged periods close to the brain, and experience suggests it is too soon to rule anything out. Finally it remains possible that children are more vulnerable to negative side-effects than adults, and their adoption of mobiles as a must-have accessory is even more recent.

Given his position, it would be strange if Professor Challis did not aim to improve on the existing science on mobile phones and health; this is his role. But his is a serious and independent voice. The precautionary principle still applies here. Manufacturers as well as users should welcome the new study.