Study type: Medical/biological study (experimental study)

GFAP expression in the rat brain following sub-chronic exposure to a 900 MHz electromagnetic field signal. med./bio.

Published in: Int J Radiat Biol 2010; 86 (5): 367-375

Aim of study (acc. to author)

To study whether exposure to a subchronic electromagnetic field exposure (for two months) to a GSM signal induces persistent astroglial activation 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

48 rats were divided into eight experimental groups. 24 rats were sacrificed three and 24 rats were sacrificed ten days after the end of exposure. Within each group of 24 rats the following groups were distinguished (each group = 6 rats): cage control, sham exposure, two exposure groups.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 900 MHz
Modulation type: pulsed
Exposure duration: continuous for 45 min/day on 5 days/week during 8 weeks
  • SAR: 1.5 W/kg average over mass (brain)
Exposure 2: 900 MHz
Modulation type: pulsed
Exposure duration: continuous for 15 min/day on 5 days/week for 8 weeks
  • SAR: 6 W/kg average over mass (brain)

Exposure 1

Main characteristics
Frequency 900 MHz
Type
Exposure duration continuous for 45 min/day on 5 days/week during 8 weeks
Modulation
Modulation type pulsed
Duty cycle 12.5 %
Repetition frequency 217 Hz
Exposure setup
Exposure source
Setup animals kept in plexiglas rockets with a truncated cone containing the loop antenna
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 continuous for 15 min/day on 5 days/week for 8 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

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 data showed that subchronic exposure to GSM microwaves for 45 min/day at a SAR value of 1.5 W/kg or for 15 min/day at a SAR value of 6 W/kg induces an increase in GFAP expression in different brain areas three and ten days after treatment .
The authors conclude that subchronic exposures to a 900 MHz electromagnetic field signal for two months could adversely affect the rat brain (sign of a potential gliosis).

Study character:

Study funded by

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