Study type: Medical/biological study (experimental study)

Electromagnetic Field Sensitivity. med./bio.

Published in: J Bioelectricity 1991; 10 (1-2): 241-256

Aim of study (acc. to author)

A multiphase study was performed to find an effective method to evaluate electromagnetic field sensitivity of patients.

Background/further details

1) The first phase developed criteria for controlled testing.
2) A second phase involved a challenge of 100 patients who complained of electromagnetic field sensitivity to a series of electromagnetic fields ranging from 0 to 5 MHz in frequency, plus 5 blank challenges (sham exposure). 25 patients were sensitive to the electromagnetic fields, but did not react to the sham exposure. These were compared in the
3rd phase to 25 healthy naive volunteer controls.
4) 16 electromagnetic field-sensitive patients were rechallenged twice to the frequencies to which they were most sensitive during the previous challenge.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 100 mHz–5 MHz
Modulation type: CW
Exposure duration: 3 min/test
Exposure 2: 100 mHz–5 MHz
Modulation type: CW
Exposure duration: 3 min/test

Exposure 1

Main characteristics
Frequency 100 mHz–5 MHz
Type
Waveform
  • rectangular
Exposure duration 3 min/test
Modulation
Modulation type CW
Exposure setup
Exposure source
Distance between exposed object and exposure source 0.3 m
Setup coil 16 cm diameter and 15 cm long, consisting of 35 m of cable, positioned on the floor of the low-pollution room; test person sitting on a chair in this room
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 2,900 nT - - - at floor level;
magnetic flux density 350 nT - - - at the chair;
magnetic flux density 70 nT - - - at hand level;

Exposure 2

Main characteristics
Frequency 100 mHz–5 MHz
Type
Waveform
  • rectangular
Exposure duration 3 min/test
Additional info f = 0.1, 0.5, 1, 2.5, 5, 10, 20, 40, 50, 60, 100 Hz, 1, 5, 10, 20, 35, 50, 75, 100 Khz, 1, 5 Mhz
Modulation
Modulation type CW
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 2,900 nT - - - -
magnetic flux density 350 nT - - - -
magnetic flux density 70 nT - - - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

1) Monitoring devices were used to ensure that extraneous electromagnetic fields would not interfere with the tests.
2) 25 patients were sensitive to the electromagnetic fields, but did not react to the sham exposure. These patients were compared to healthy naive volunteer controls (third phase). None of the volunteers reacted to any challenge, i.e. exposure or sham exposure, but 16 of the electromagnetic field-sensitive patients had positive signs and symptoms, plus autonomic nervous system changes.
4) The active frequency (exposure) was found to be positive in 100 % of the challenges, while all of the placebo tests were negative.
The authors conclude that the data give strong evidence that electromagnetic field sensitivity exists, and can be elicited under environmentally controlled conditions. Further studies are needed to investigate the effects of electromagnetic fields on human health.

Study character:

Study funded by

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