Study type: Medical/biological study (experimental study)

Cognitive impairment in rats after long-term exposure to GSM-900 mobile phone radiation. med./bio.

Published in: Bioelectromagnetics 2008; 29 (3): 219-232

Aim of study (acc. to author)

To evaluate whether long-term exposure to GSM mobile phones might give rise to changes in cognitive functions, the authors exposed male and female rats to GSM mobile phone electromagnetic fields for 2 h once a week for a total of 55 weeks.

Background/further details

Out of a total of 56 rats, 32 rats were exposed (two groups at different SAR values), 16 animals were sham exposed and 8 animals were cage controls.
Behavioural tests were performed during a period from 3 to 7 weeks after the last exposure or sham exposure.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 900 MHz
Modulation type: pulsed
Exposure duration: 2 h/week for 55 weeks
  • SAR: 0.6 mW/kg average over mass (whole body) (at 33 mW/m²)
  • SAR: 60 mW/kg average over mass (whole body) (at 3.3 W/m²)
  • power density: 33 mW/m²
  • power density: 3.3 W/m²

General information

animals were treated in three groups: i) exposure to GSM ii) sham exposure iii) cage control

Exposure 1

Main characteristics
Frequency 900 MHz
Type
Exposure duration 2 h/week for 55 weeks
Modulation
Modulation type pulsed
Exposure setup
Exposure source
Setup GSM test phone connected to four TEM cells, rats placed on plastic trays in the TEM cells
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
SAR 0.6 mW/kg average over mass calculated whole body at 33 mW/m²
SAR 60 mW/kg average over mass calculated whole body at 3.3 W/m²
power density 33 mW/m² - - - -
power density 3.3 W/m² - - - -

Reference articles

  • Crawford ML (2016): Generation of standard EM fields using TEM transmission cells
  • Belyaev IY et al. (2006): Exposure of rat brain to 915 MHz GSM microwaves induces changes in gene expression but not double stranded DNA breaks or effects on chromatin conformation.
  • Salford LG et al. (2003): Nerve cell damage in mammalian brain after exposure to microwaves from GSM mobile phones.
  • Persson BRR et al. (1997): Blood-brain barrier permeability in rats exposed to electromagnetic fields used in wireless communication.
  • Salford LG et al. (1994): Permeability of the blood-brain barrier induced by 915 MHz electromagnetic radiation, continuous wave and modulated at 8, 16, 50, and 200 Hz.
  • Salford LG et al. (1993): Permeability of the blood-brain barrier induced by 915 MHz electromagnetic radiation, continuous wave and modulated at 8, 16, 50 and 200 Hz.

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

The exposed rats (both groups) showed a significant impairment in episodic-like memory when compared to that of sham exposed animals. Exposed rats had impaired memory for objects and their temporal order of presentation compared to sham exposed rats. The observed impairment following exposure cannot be attributed to acute stress, because tests were performed during a period of 3-7 weeks after the last exposure.
In the open field test no difference was found.
The data suggest significantly reduced memory functions in rats after GSM microwave exposure.

Study character:

Study funded by

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