Study type: Medical/biological study (experimental study)

Absence of daytime 50 Hz, 100 microT(rms) magnetic field or bright light exposure effect on human performance and psychophysiological parameters. med./bio.

Published in: Bioelectromagnetics 2005; 26 (3): 225-233

Aim of study (acc. to author)

To reproduce and extend two earlier studies of the effects of human exposure to 50 Hz magnetic fields (publication 3569).

Background/further details

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).

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: continuous for 30 min

General information

Subjects were exposed to 3 experimental sessions consisting of 50 Hz magnetic field exposure, sham exposure and bright light (5000 lux) exposure.

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration continuous for 30 min
Exposure setup
Exposure source
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.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 100 µT effective value measured - -

Reference articles

  • Crasson M et al. (1999): 50 Hz magnetic field exposure influence on human performance and psychophysiological parameters: two double-blind experimental studies.

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Investigated organ system:
Time of investigation:
  • before exposure
  • during exposure
  • after exposure

Main outcome of study (acc. to author)

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.

Study character:

Study funded by

Related articles