To reproduce and extend two earlier studies of the effects of human exposure to 50 Hz magnetic fields (publication 3569).
In the recent paper, the results of two double-blind investigations performed to examine effects of 100 µT 50 Hz magnetic field exposure on psychological parameters in the same group of healthy human volunteers were described.
In the present study, another group of 18 healthy subjects were exposed to three experimental sessions of 30 min each, given at 1 week intervals (the sessions consisted of continuous 100 µT 50 Hz magnetic field exposure, sham exposure, and bright light (5000 lux) exposure which was intended to be a positive control).
Exposure duration: continuous for 30 min
Subjects were exposed to 3 experimental sessions consisting of 50 Hz magnetic field exposure, sham exposure and bright light (5000 lux) exposure.
|Exposure duration||continuous for 30 min|
|Setup||Subjects were seated in the exposure facility with their heads placed in the magnetic helmet which produced a magnetic field that was directed from right mandibula to left parietal site of the head.|
|Additional info||The helmet was formed by six Helmholtz coils distributed in three orthogonal directions. During the exposure one vertical and one horizontal pair of coils was energized.|
|magnetic flux density||100 µT||effective value||measured||-||-|
The results on mood, event-related potentials, reaction time, and other performance measures did not show any differences among the sham exposure, light exposure, and magnetic field exposure conditions.
The data of this study do not support the hypothesis that extremely low frequency magnetic field exposure affects the brain's electrical activity or cognitive function at field strength similar to that found in very close proximity of some household and industrial electrical appliances and well in excess of the average magnetic field strength found in homes.
The sensitivity of the experiment was possibly not sufficient to detect an effect at this relatively low magnetic field. Larger sample sizes would be required in further studies.