Study type: Medical/biological study (experimental study)

GSM mobile phone radiation suppresses brain glucose metabolism. med./bio.

Published in: J Cereb Blood Flow Metab 2011; 31 (12): 2293-2301

Aim of study (acc. to author)

To study if acute cell phone exposure affects brain glucose metabolism, a marker of brain activity.

Background/further details

13 male subjects were exposed and sham exposed (with an interval of at least six days) while performing a simple visual vigilance task (to minimize differences in cognitive states between the exposure conditions). Positron emission tomography scans were performed after 30 minutes of exposure (when fluorodeoxyglucose was mostly taken up by the brain tissue).

Endpoint

Exposure

Exposure Parameters
Exposure 1: 902.4 MHz
Modulation type: pulsed
Exposure duration: continuous for 33 min
  • power: 240 mW
  • SAR: 1.1 W/kg average over mass (10 g) (at the left ear)
  • SAR: 1 W/kg average over mass (10 g) (at the right ear)
  • SAR: 1.5 W/kg average over mass (1 g) (at the left ear)
  • SAR: 1.4 W/kg average over mass (1 g) (at the right ear)
  • SAR: 0.74 W/kg maximum (10 g) (head)
  • SAR: 0.23 W/kg maximum (10 g) (brain)

Exposure 1

Main characteristics
Frequency 902.4 MHz
Type
Exposure duration continuous for 33 min
Modulation
Modulation type pulsed
Additional info

burst time: 0.577 ms burst repetition time: 4.615 ms

Exposure setup
Exposure source
Setup two modified phones (transmitter deactivated, loudspeaker and battery removed) attached so to a plastic helmet that the phones were in normal phoning position at the ears of the test person; only the phone on the right side transmitted a signal during exposure; phones modified to eliminate temperature rise of the chassis and to gain a constant output power; signal transmitted via a coaxial cable from an identical phone
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
power 240 mW - - - -
SAR 1.1 W/kg average over mass measured 10 g at the left ear
SAR 1 W/kg average over mass measured 10 g at the right ear
SAR 1.5 W/kg average over mass measured 1 g at the left ear
SAR 1.4 W/kg average over mass measured 1 g at the right ear
SAR 0.74 W/kg maximum calculated 10 g head
SAR 0.23 W/kg maximum calculated 10 g brain

Reference articles

  • Christ A et al. (2010): The Virtual Family--development of surface-based anatomical models of two adults and two children for dosimetric simulations.
  • Boutry CM et al. (2008): Dosimetric evaluation and comparison of different RF exposure apparatuses used in human volunteer studies.
  • Kuster N et al. (2004): Guidance for exposure design of human studies addressing health risk evaluations of mobile phones.

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)

The data revealed local suppressive effects of a 30 minute exposure to GSM mobile phone on relative cerebral metabolic rate of glucose in the temporal and temporoparietal cortex of the exposed hemisphere. Temperature rise was also observed on the exposed side of the head, but the magnitude was very small (<0.21°C). The exposure did not affect the vigilance task performance.
The results showed that short-term mobile phone exposure can locally suppress brain energy metabolism in humans.

Study character:

Study funded by

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