Study type: Medical/biological study (experimental study)

50 Hz magnetic field exposure influence on human performance and psychophysiological parameters: two double-blind experimental studies. med./bio.

Published in: Bioelectromagnetics 1999; 20 (8): 474-486

Aim of study (acc. to author)

Two double-blind studies were performed to examine magnetic field exposure effects and to determine the impact of temporal variation (continuous versus intermittent exposure) of magnetic field diurnal exposure on psychological and psychophysiological parameters in healthy humans.

Background/further details

Three exposure sessions of 30 min, i.e., sham, continuous, and intermittent (15 s ON/OFF cycles) magnetic field conditions, were involved. Each subject participated in all sessions, which were spaced at one week intervals.
In experiment 1, 21 healthy male volunteers were studied (ten subjects were exposed at 13:30 h, and 11 subjects were exposed at 16:30 h). Eighteen of the 21 volunteers took part in experiment 2, undertaken to better understand the data related to information processing. Exposure time was at 13:30 h.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: continuous for 30 min
Exposure 2: 50 Hz
Exposure duration: intermittent for 30 min; 15 s ON/OFF cycle

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.
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 were energized.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 100 µT effective value measured - -

Exposure 2

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration intermittent for 30 min; 15 s ON/OFF cycle
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 100 µT peak value measured - -

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)

Experiment 1: Statistically significant changes in the amplitude of event-related potentials were revealed after magnetic field exposure in the dichotic listening task.
Experiment 2: The analysis of the data again revealed significant amplitude changes of the event-related potentials recorded in the dichotic listening task. Moreover, they demonstrated event-related potentials latency and reaction time slowing in the oddball paradigm. These data also indicate that a low level 50 Hz magnetic field may have a slight influence on event-related potentials and reaction time under specific circumstances of sustained attention.

Study character:

Study funded by

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