Study type: Medical/biological study (experimental study)

Effect of global system for mobile communication (GSM) microwave exposure on blood-brain barrier permeability in rat. med./bio.

Published in: Acta Neuropathol 1997; 94 (5): 465-470

Aim of study (acc. to author)

To analyze the immediate and late effects of 4 h microwave exposure on the permeability of the blood-brain barrier using a novel exposure system which simulates the absorption characteristics of cellular phones operating in the 900 MHz frequency band in the heads of rats maintained in a fixed position in relation to the antenna.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 900 MHz
Modulation type: pulsed
Exposure duration: continuous for 4 h
  • SAR: 0.3 W/kg average over mass (brain)
  • SAR: 1.5 W/kg average over mass (brain)
Exposure 2: 900 MHz
Modulation type: CW
Exposure duration: continuous for 4 h
  • SAR: 7.5 W/kg average over mass (brain)

Exposure 1

Main characteristics
Frequency 900 MHz
Type
Exposure duration continuous for 4 h
Modulation
Modulation type pulsed
Repetition frequency 217 Hz
Exposure setup
Exposure source
  • central antenna, for details see reference article
Chamber Plexiglas carousel
Setup Rats were restrained in plastic tubes mounted circularly in a Plexiglas carousel with the head towards the antenna.
Additional info As negative control two groups were used: a freely moving control group and a sham exposed group which was restrained for 4 h in the exposure system. As positive controls, focal BBB disturbances were produced in two rats by cold injury.
Parameters
Measurand Value Type Method Mass Remarks
SAR 0.3 W/kg average over mass unspecified brain -
SAR 1.5 W/kg average over mass unspecified brain -

Exposure 2

Main characteristics
Frequency 900 MHz
Type
Exposure duration continuous for 4 h
Modulation
Modulation type CW
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
SAR 7.5 W/kg average over mass unspecified brain -

Reference articles

  • Fritze K et al. (1997): Effect of global system for mobile communication microwave exposure on the genomic response of the rat brain.

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

The increase in serum albumin extravasations after microwave exposure reached significance only in the group exposed to the highest SAR of 7.5 W/kg. Histological injury was not observed in any of the examined brains. The study demonstrates that microwave irradiation in the frequency and intensity range of mobile telephony is unlikely to produce pathologically significant changes of the blood-brain barrier permeability.

Study character:

Study funded by

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