Study type: Medical/biological study (experimental study)

Effect of a chronic GSM 900 MHz exposure on glia in the rat brain. med./bio.

Published in: Biomed Pharmacother 2008; 62 (4): 273-281

Aim of study (acc. to author)

To study glial evolution 10 days after a chronic exposure (5 days a week for 24 weeks) to a GSM signal (45 min/day) measuring GFAP expression in five different rat brain areas (prefrontal cortex, caudate-putamen, lateral globus pallidus of striatum, dentate gyrus of hippocampus, and cerebellum cortex).

Background/further details

24 rats were used and divided in four experimental groups (cage control, sham exposure, two exposure groups; n=6).

Endpoint

Exposure

Exposure Parameters
Exposure 1: 900 MHz
Modulation type: pulsed
Exposure duration: 45 min/day, 5 days/week for 24 weeks
  • SAR: 1.5 W/kg average over mass (brain)
Exposure 2: 900 MHz
Modulation type: pulsed
Exposure duration: 15 min/day, 5 days/week for 24 weeks
  • SAR: 6 W/kg average over mass (brain)

Exposure 1

Main characteristics
Frequency 900 MHz
Type
Exposure duration 45 min/day, 5 days/week for 24 weeks
Modulation
Modulation type pulsed
Duty cycle 12.5 %
Repetition frequency 217 Hz
Exposure setup
Exposure source
Setup rats placed in plexiglas rockets with truncated cones with individual loop antennas; rat's head placed in the cone
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
SAR 1.5 W/kg average over mass calculated brain -

Exposure 2

Main characteristics
Frequency 900 MHz
Type
Exposure duration 15 min/day, 5 days/week for 24 weeks
Modulation
Modulation type pulsed
Duty cycle 12.5 %
Repetition frequency 217 Hz
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
SAR 6 W/kg average over mass calculated brain -

Reference articles

  • Brillaud E et al. (2007): Effect of an acute 900MHz GSM exposure on glia in the rat brain: a time-dependent study.
  • Dubreuil D et al. (2002): Does head-only exposure to GSM-900 electromagnetic fields affect the performance of rats in spatial learning tasks?
  • Mausset AL et al. (2001): Effects of radiofrequency exposure on the GABAergic system in the rat cerebellum: clues from semi-quantitative immunohistochemistry.

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

Rats exposed to chronic GSM signal at 6 W/kg have increased GFAP stained surface areas in the brain in comparison to sham exposed or cage control animals. But the chronic exposure at 1.5 W/kg did not increase GFAP expression.
The data indicate that chronic exposure to GSM 900 MHz microwaves (SAR=6 W/kg) may induce persistent astroglia activation in the rat brain (sign of cellular change and a potential gliosis).

Study character:

Study funded by

Related articles