Researchers investigating the health effects of mobile phone masts have found that sufferers report symptoms regardless of whether the equipment is actually on or off.
The academic investigators were led by Professor Elaine Fox of the University of Essex, and their report (pdf) was published by Environmental Health Perspectives, a peer-reviewed journal run by the National Institute of Environmental Health Sciences.
During the study, 56 people who said they suffered adverse health effects from mobile mast transmissions were compared with 120 controls. Twelve of the professedly mast-sensitive individuals dropped out after the "open" testing, in which subjects were told whether or not a transmission was actually happening, as did five controls.
The remaining 44 mast-sensitives and 115 controls were then put through "double-blind" tests in which neither they nor the researchers knew whether the equipment was transmitting. The trials employed both GSM and UMTS transmissions.
A few of the subjects correctly guessed the answer every time, but the report authors said that was to be expected.
"Participant performance for each group did not differ from chance," they wrote.
There was an apparent correlation at first between UMTS signals and the sensitive group's reports of "arousal", but the scientists said this was caused by the fact that the random test equipment happened to generate a lot of UMTS transmissions during early stages, when the subjects were anxious.
According to the researchers, the trial results showed that "exposure from mobile phone technology is not related to levels of well-being or physical symptoms in [mast-sensitive] individuals".
"Furthermore, [mast-sensitive] individuals are unable to detect the presence of [transmissions] under double-blind conditions. It remains the case however, that [mast-sensitive] individuals present with a range of distressing and serious symptoms and often have a very poor quality of life."
It seems that the presence of mobile phone masts can indeed make people severely ill, but this has nothing to with radio waves - and probably everything to do with the fact that the sufferers expect to be harmed.
Professor Fox told the BBC that "belief is a very powerful thing .. If you really believe something is going to do you some harm, it will."
So now we only need to worry about the dangers of Wi-Fi...®