Study type: Medical/biological study (experimental study)

Alterations in Human EEG Activity Caused by Extremely Low Frequency Electromagnetic Fields. med./bio.

Published in: IEEE 28th Annual International Conference of the Engineering in Medicine and Biology Society (EMBC), 2006. IEEE, 2006: 3206-3209, ISBN 9781424400324

Aim of study (acc. to author)

The purpose of this study was to investigate whether combined exposure to extremely low frequency fields (50, 16.66, 13, 10, 8.33 and 4Hz) could cause changes in the human EEG activity.

Background/further details

The experiments were conducted on 33 healthy subjects (24 men and 9 women) in the age range of 20-59 years. Each subject participated in two sessions: one session included the sham exposure and the other session consisted of the exposure set-up with exposure periods for 2 minutes at each frequency, beginning with the highest frequency in a decreasing order and in between one minute EEG recording without exposure. One half of the subjects received exposure followed by sham exposure (exposure 1, sham exposure 2) , the other half was sham exposed first, followed by exposure (sham exposure 1, exposure 2).

Endpoint

Exposure

Exposure Parameters
Exposure 1: 4–50 Hz
Exposure duration: 2 min exposure, 1 min rest, 2 min exposure etc. for 19 min

Exposure 1

Main characteristics
Frequency 4–50 Hz
Type
Waveform
Polarization
Exposure duration 2 min exposure, 1 min rest, 2 min exposure etc. for 19 min
Exposure setup
Exposure source
Chamber test person lies between the coils in a darkened and sound proof RF anechoic chamber
Setup pair of circular Helmoltz coils with a radius of 65 cm and 250 turns of 0.8 mm copper wire each; exposure over the head of the test person; field perpendicular to the earth's north-south magnetic field
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 20 µT effective value measured - +/- 0.57 µT

Reference articles

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

The exposure 1 (group which was exposed first, followed by sham exposure) indicated a significant increase in beta waves at the frontal brain region, and a significant decrease in the alpha waves in parietal and occipital brain regions in the exposure 2 (exposure was conducted after sham exposure) . Significant decrease in the alpha waves at the occipital brain regions were observed in sham exposure 2 (sham exposure which followed electromagnetic irradiation).

Study character:

Study funded by

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