Study type: Medical/biological study (experimental study)

Provocation study of persons with perceived electrical hypersensitivity and controls using magnetic field exposure and recording of electrophysiological characteristics. med./bio.

Published in: Bioelectromagnetics 2001; 22 (7): 457-462

Aim of study (acc. to author)

To conduct an neurophysiological examination of possible effects of exposure to a low-level 60 Hz magnetic field on persons with perceived electromagnetic hypersensitivity and controls ("groups") during rest and performance of a mental arithmetic task ("condition").

Background/further details

Twenty subjects (15 female and 5 male) with perceived electromagnetic hypersensitivity and twenty volunteers as control group took part in the study. The session lasted 40 minutes, divided into two ten minutes rest periods and two ten minutes periods of mathematical performance. Magnetic field and sham exposures were presented randomly in four conditions: Field-Rest, Sham-Rest, Field-Math, and Sham-Math.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: 10 min intermittent 15 s on/off

General information

test sessions were divided into 4 conditions of 10 min each: i) EMF + rest ii) sham field + rest iii) EMF + mathematical test iv) sham + mathematical test

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration 10 min intermittent 15 s on/off
Exposure setup
Exposure source
Setup three square coils with 140 cm sides and 10 turns of 0.5 mm² insulated, tinned copper wire arranged around the armchair in which the subject was seated 1 m from a monitor; the lower coil was positioned at the floor, the second 80 cm and the third 160 cm above the floor
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 10 µT effective 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)

No participants of both groups could reliably report the presence or absence of the magnetic field. Significant differences between subjects with perceived electrical hypersensitivity and controls (group factor without exposure) were observed in heart rate, heart rate variability, and electrodermal activity whereas the EEG characteristics showed no differences between the two groups. Analysis of the condition factor (rest versus arithmetic task) indicated main effects for heart rate, heart rate variability, electrodermal activity, and the alpha waves and theta waves of EEG. Magnetic field exposure did not affect autonomous system or EEG variables of either groups.
The authors concluded that there was no indication that the persons with perceived electrical hypersensitivity and controls were affected by low-level 60 Hz magnetic field exposure. However, differences in the baseline physiological variables were observed between both groups.

Study character:

Study funded by

Related articles