Study type: Medical/biological study (experimental study)

Polluted places or polluted minds? An experimental sham-exposure study on background psychological factors of symptom formation in 'Idiophatic Environmental Intolerance attributed to electromagnetic fields'. med./bio.

Published in: Int J Hyg Environ Health 2010; 213 (5): 387-394

Aim of study (acc. to author)

The aim of the present study was twofold: 1) to demonstrate the significant role of the nocebo effect in physical symptoms reported at 50 Hz electromagnetic field exposure (by means of sham exposure accompanied by suggestions about the presence of a low and a high intensity electromagnetic field, respectively; 2) to investigate nocebo-related personality characteristics as psychological risk factors in electrosensitivity.

Background/further details

40 healthy subjects (university students) participated.
The authors hypothesized that increased perception of symptoms as well as of the presence of an exposure would be reported by participants with larger self-rated electrosensitivity, and in the presumed presence of higher intensity electromagnetic fields. In addition, higher somatisation and somatosensory amplification scores, increased anxiety during the experiment, and lower optimism scores were hypothesized to correlate with increased reporting of symptoms and self-rating of electrosensitivity.

Endpoint

Exposure

Exposure Parameters
Exposure 1:
  • unspecified
Exposure duration: two times 10 min
-

Exposure 1

Main characteristics
Frequency
  • unspecified
Type
Exposure duration two times 10 min
Exposure setup
Exposure source
Setup test person sitting on a chair above Helmholtz coils which were only virtually connected to the power supply and therefore could not emit any field; test persons believed to be exposed to a weak field during the first 10 min and to a high intensity field for the last 10 min
Sham exposure A sham exposure was conducted.
Parameters

No parameters are specified for this exposure.

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)

Subjects with higher self-rated electrosensitivity scores expected and experienced more symptoms. Suggestion of stronger electromagnetic field exposure resulted in larger symptom scores and enhanced field-perception as compared to the presumed weaker exposure. Experienced symptom scores correlated primarily with somatisation scores, whereas self-rating of electrosensitivity correlated with somatosensory amplification scores.
In conclusion, the findings confirm that there is considerable nocebo effect in symptom reports related to 50 Hz electromagnetic fields. Electrosensitivity seems to be formed through psychosocial factors, such as enhanced risk perception and expectations, self-monitoring, somatisation and somatosensory amplification.

Study character:

Study funded by

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