Study type: Medical/biological study (experimental study)

Effects of mobile phone signals over BOLD response while performing a cognitive task. med./bio.

Published in: Clin Neurophysiol 2012; 123 (1): 129-136

Aim of study (acc. to author)

To study the effects of an exposure to a GSM signal on brain BOLD (blood-oxygen-level dependent) response, as well as its time course while performing a reaction time task.

Background/further details

12 young men participated (age range: 19-25) and underwent two sessions separated by one week (exposure/sham exposure session).

Endpoint

Exposure

Exposure Parameters
Exposure 1: 902.4 MHz
Modulation type: pulsed
Exposure duration: continuous for 45 min
  • power: 2 W peak value
  • power: 0.25 W average over time
  • SAR: 1.25 W/kg (at superficial level)
  • SAR: 0.5 W/kg maximum (at 2 cm depth in a phantom)
  • SAR: 0.212 W/kg minimum (at 5 cm depth in a phantom)

Exposure 1

Main characteristics
Frequency 902.4 MHz
Type
Exposure duration continuous for 45 min
Modulation
Modulation type pulsed
Repetition frequency 217 Hz
Additional info

second modulation frequency: 8.33 Hz

Exposure setup
Exposure source
Distance between exposed object and exposure source 1.5 cm
Setup mobile phone set by a test card to transmit a typical basic GSM signal; phone held by a helmet in a typical phoning position over the right ear with the antenna oriented to the temporo-parietal area and the microphone oriented towards the mouth; identical phone without battery placed on the left side of the helmet; subjects could move freely during exposure or sham exposure; subjects performed two sessions, separated by one week
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
power 2 W peak value - - -
power 0.25 W average over time - - -
SAR 1.25 W/kg - measured - at superficial level
SAR 0.5 W/kg maximum measured - at 2 cm depth in a phantom
SAR 0.212 W/kg minimum measured - at 5 cm depth in a phantom

Reference articles

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

The data did not detect any brain activity changes by mobile phones. Also reaction times in the somatosensory task were not affected.
In conclusion, no changes in BOLD response have been observed as a consequence of radiofrequency electromagnetic field exposure.

Study character:

Study funded by

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