Study type: Medical/biological study (experimental study)

Head-only exposure to GSM 900-MHz electromagnetic fields does not alter rat's memory in spatial and non-spatial tasks. med./bio.

Published in: Behav Brain Res 2003; 145 (1-2): 51-61

Aim of study (acc. to author)

The study is a follow-up of previous work (publication 8336) on the effects of head-only exposure of rats to GSM electromagnetic fields. There were two main objectives: to study GSM effects on spatial memory with more complex procedures, and to enlarge the investigation

Endpoint

Exposure

Exposure Parameters
Exposure 1: 900 MHz
Modulation type: pulsed
Exposure duration: repeated daily exposure for 45 min for 7, 9 or 12 days
  • SAR: 1 W/kg average over mass (brain)
  • SAR: 3.5 W/kg average over mass (brain)
Exposure 2: 900 MHz
Modulation type: pulsed
Exposure duration: repeated exposure for 45 min, 2 days apart
  • SAR: 1 W/kg average over mass (brain)
  • SAR: 3.5 W/kg average over mass (brain)

Exposure 1

Main characteristics
Frequency 900 MHz
Type
Exposure duration repeated daily exposure for 45 min for 7, 9 or 12 days
Modulation
Modulation type pulsed
Duty cycle 12.5 %
Repetition frequency 217 Hz
Exposure setup
Exposure source
Setup During exposure, rats were restrained in rockets made of 5-mm-thick Plexiglas and consisting of a cylinder (6 cm diameter, 15 cm length) and a truncated cone (3 cm length) in which the rat inserted its head. The loop antenna was placed against the cone directly above the rat's head. The four rockets for simultaneous exposure were separated from each other by a double layer of a 12 cm absorbing material to prevent interference from one antenna to another.
Additional info The performances of exposed rats were compared to those of sham-exposed and cage-control rats.
Parameters
Measurand Value Type Method Mass Remarks
SAR 1 W/kg average over mass measured and calculated brain -
SAR 3.5 W/kg average over mass measured and calculated brain -

Exposure 2

Main characteristics
Frequency 900 MHz
Type
Exposure duration repeated exposure for 45 min, 2 days apart
Modulation
Modulation type pulsed
Duty cycle 12.5 %
Repetition frequency 217 Hz
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
SAR 1 W/kg average over mass measured and calculated brain -
SAR 3.5 W/kg average over mass measured and calculated brain -

Reference articles

  • Dubreuil D et al. (2002): Does head-only exposure to GSM-900 electromagnetic fields affect the performance of rats in spatial learning tasks?
  • Chou CK et al. (1999): Development of a rat head exposure system for simulating human exposure to RF fields from handheld wireless telephones.

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

In one of the spatial memory tasks (without delay), a slightly improved performance was found after 3.5 W/kg exposure, a result that was not observed in the other spatial memory task (with an intra-trial delay). In the non-spatial memory task (object recognition task), although some effects on exploratory activity were found, recognition memory was unaffected in exposed rats. Altogether, this set of experiments provides no evidence indicating that spatial and non-spatial memory can be affected by an exposure to 900 MHz GSM electromagnetic fields.

Study character:

Study funded by

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