Study type: Medical/biological study (experimental study)

Effects of microwaves emitted by cellular phones on human slow brain potentials. med./bio.

Published in: Bioelectromagnetics 1998; 19 (6): 384-387

Aim of study (acc. to author)

To study the influence of electromagnetic fields generated by cellular phones on preparatory slow brain potentials (SP), which occur prior to voluntary initiated movements.

Background/further details

The influence of electromagnetic field exposure on SP was investigated in two different experimental tasks: In the first, healthy male subjects had to perform simple self-paced finger movements to elicit a Bereitschaftspotential; in the second, they performed a complex and cognitive visual monitoring task.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 916.2 MHz
Modulation type: pulsed
Exposure duration: continuous for about 3 or 5 min per task
  • power: 2.8 W peak value
  • power: 350 mW average over time
  • SAR: 1.42 mW/g average over mass (1 g)
  • SAR: 0.882 mW/g average over mass (10 g)

Exposure 1

Main characteristics
Frequency 916.2 MHz
Type
Exposure duration continuous for about 3 or 5 min per task
Modulation
Modulation type pulsed
Pulse width 577 µs
Repetition frequency 217 Hz
Additional info

no acoustic signal transmission nor power management

Exposure setup
Exposure source
Setup A digital mobile telephone with extended antenna was positioned in direct contact to the left ear of the subjects. The devices for generating the pulsed electromagnetic energy were operated from a separate room using an extension lead.
Additional info Tasks were performed with and without EMF exposure single-blind and counterbalanced between subjects.
Parameters
Measurand Value Type Method Mass Remarks
power 2.8 W peak value measured - -
power 350 mW average over time measured - -
SAR 1.42 mW/g average over mass measured 1 g -
SAR 0.882 mW/g average over mass measured 10 g -

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

In the simple finger movement task, no significant electromagnetic field effects on Bereitschaftspotential-parameters were revealed. Although performance parameters in the visual monitoring task did not differ between the exposure and the sham-exposure conditions, slow brain potential parameters show distinct electromagnetic field influence: exposure effected a significant decrease of slow brain potentials at central and temporo-parieto-occipital brain regions, but not at the frontal one.

Study character:

Study funded by

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