Study type: Medical/biological study (experimental study)

Human brain activity during exposure to radiofrequency fields emitted by cellular phones. med./bio.

Published in: Scand J Work Environ Health 2000; 26 (2): 87-92

Aim of study (acc. to author)

To explore the possible influence of radiofrequency fields (emitted by 5 different cellular phones) on human brain functions.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 900–1,800 MHz
Exposure duration: repeated exposure trials for 30 min with 20 min of real exposure
  • power: 2 W (1-2 W)
  • SAR: 850 mW/g (0.851-0.818 mW/g)

Exposure 1

Main characteristics
Frequency 900–1,800 MHz
Type
Exposure duration repeated exposure trials for 30 min with 20 min of real exposure
Additional info Four mobile phones operated at 900 MHz and one at 1800 MHz.
Modulation
Modulation type cf. additional info
Additional info

NMT, GSM, or PCN

Exposure setup
Exposure source
Distance between exposed object and exposure source 1 cm
Setup Three different analogue 900 MHz NMT phones were used with either a helix, fixed whip, or extended whip antenna as well as two digital phones operating at 900 MHz (GSM) and at 1800 MHz (PCN), respectively. The phones were operated via a computer and without sound transmission (single-blind). The phones which were not held by the test persons were located 1 ± 0.5 cm from the head while the subjects were seated in a comfortable chair.
Additional info Five exposure trials of 30 min were performed each with 20 min of RF exposure and 5 min of sham exposure before and after the real exposure. Apart from this there was a separate 30 min sham exposure trial. The order of different exposure conditions was randomised. Only one test per day was done for each subject.
Parameters
Measurand Value Type Method Mass Remarks
power 2 W - - - 1-2 W
SAR 850 mW/g - measured and calculated 10 g 0.851-0.818 mW/g

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

Radiation to one of the phones caused a statistically significant change in the absolute power at the delta band of the EEG recording. However, no difference was found in the relative power of the same band, and no changes occured during radiation to other phones at any frequency bands. The data suggest that exposure to radiofrequency field emitted by cellular phones has no abnormal effects on EEG activity. The observed difference in one parameter was probably caused by statistical chance.

Study character:

Study funded by

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