Study type: Medical/biological study (experimental study)

Effects of GSM signals on auditory evoked responses. med./bio.

Published in: Bioelectromagnetics 2005; 26 (5): 341-350

Aim of study (acc. to author)

To investigate the influence of radiofrequency fields emitted by GSM (Global System for Mobile Communications) phones on the human cerebral activity. The auditory evoked potentials (AEPs) of healthy humans and epileptic patients were analyzed.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 900 MHz
Modulation type: pulsed

Exposure 1

Main characteristics
Frequency 900 MHz
Type
Modulation
Modulation type pulsed
Exposure setup
Exposure source
Chamber Subjects were seated in a soundproof Faraday screened room, wearing a 32-electrode helmet. The phone was placed on the electrode helmet close to the right ear using a plastic structure without metal parts.
Setup Two 24-ms sine wave sound stimuli of 500 Hz and 1 kHz in random order (250 times each) were heard through the phone once every second. The experimental sessions consisted of four phases: no RF emission, minimal RF emission (-30 dB), maximal RF emission, and again minimal RF emission. Control of the RF emission power was achieved using a communication simulator.
Additional info Every subject participated in experimental and control sessions at an interval of several days. The type of session was not known to the subject. In this study, only AEPs recorded in phase 1 and phase 3 were considered.
Parameters
Measurand Value Type Method Mass Remarks
SAR 1.4 W/kg average over mass unspecified 10 g maximum emission phase
power 0.25 W mean - - maximum emission phase
power 0.25 mW mean - - minimum emission phase

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)

Differences in the time and frequency domains of auditory evoked potentials (AEPs) with and without exposure to radiofrequency were observed for healthy persons and epileptic patients.
However, it was difficult to evaluate the modifications brought on by the radiofrequency and to deduce the effect of radiofrequency to human health. The alterations did not allow the authors to put forward some electrophysiological hypothesis.

Study character:

Study funded by

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