But the revolution that their use has brought has been accompanied by a groundswell of worry about possible long-term health hazards, and eruptions of local concern about the siting of radio masts near schools and hospitals. After a series of inconclusive or disputed reports, the national radiological protection board, a government agency, sponsored an independent group of scientists and lay people, chaired by Sir William, a former government chief scientific adviser, to look at all the evidence and all the issues. However, since the 1970s onwards there has been a number of studies in reputable laboratories in the US and Europe, suggesting subtle biological effects. High energy, short wavelength gamma rays and x-rays can burn cells and trigger cancers. But mobiles are held closer to the ear, so more radiation penetrates the skull.
Nobody knows where the dangers start.
Sunbathing warms up the brain by 10 times as much. So does jogging. That question cannot be answered finally until millions have used them for many years. The experts want more studies of the workers most at risk, and more studies of the effects of radiation. But at the moment, they don't think so.