The electromagnetic radiation emitted by mobile handsets and mobile network antennas has been the subject of controversy for some time now. Whereas people who claim to be affected by magnetic fields complain about adverse effects on their health, skeptics consider these to be the brain children of hysterical esoterics. These "electro-sensitives," as they are known to science, put down a number of complaints to electromagnetic emissions whose intensity is below the mandatory exposure limits and should therefore have no discernible biological effects. 

The Federal Institute for Occupational Safety and Health (BAuA) chose to investigate these phenomena in the context of a study that was presented at a BAuA event in Berlin at the beginning of November. If "electro-sensitivity" has a biological basis, the reasoning behind the hypothesis underlying the study goes, there should be a measurable, i.e. physiological, reaction by the human body to stimulation by an electromagnetic field. In the course of the study a total of 144 persons were in a laboratory that was neutral as to electromagnetic fields subjected within one hour three times for a period of 10 minutes to a 50 Hertz magnetic field or a pulsed GSM signal from a mobile handset with a transmitting power of 2 watts. The subjects were not told when and for how long they were being exposed to radiation. The researchers used the electrochemical reaction of the skin of the experimentees to measure their physiological reactions; in addition the experimentees were asked to give their subjective impressions.

The researchers tried to find out whether the radiation had a perceptible effect on the conductivity of the experimentees' skin, and whether there was any discernible difference between "electro-sensitives" (48 participants) and persons who claimed not to be affected by electromagnetic radiation (96 participants) with regard to the subjective perception of the presence of electromagnetic fields and their source-dependent type. In not a single instance were the researchers able to detect a change to the conductivity of an experimentee's skin. In terms of subjective detection of the fields the "electro-sensitives" also failed to achieve a higher score than the control group, although the number of times the former group claimed to sense a field was above average.

Thus the scientists when summing up the results of their study come to this conclusion: These indicate that the phenomenon of "electromagnetic hypersensitivity" cannot be put down to a measurable, biologically-based sensitivity to common electromagnetic fields. (Robert W. Smith) / (jk/c't)