Recent research has linked radiation from mobiles to cancer and brain damage. And many studies have found disturbing symptoms in people near masts.
Professor Olle Johansson, of Sweden's Karolinska Institute, who is concerned about the spread of Wi-Fi, says "thousands" of articles in scientific literature demonstrate "adverse health effects" from Wi-Fi.
"Do we not know enough already to say, 'stop'?"
For the past 16 months, the provincial government of Salzburg in Austria has been advising schools not to install Wi-Fi, and is considering a ban."