Study type: Medical/biological study (experimental study)

Effects of acute exposure to a 1439 MHz electromagnetic field on the microcirculatory parameters in rat brain. med./bio.

Published in: In Vivo 2007; 21 (4): 555-562

Aim of study (acc. to author)

To study the effects of radiofrequency electromagnetic fields on cerebral microcirculation, including blood-brain barrier function, in rat brain.

Background/further details

Rats were exposed under anesthesia. A "closed cranial window" was implanted into the parietal region.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 1,439 MHz
Modulation type: pulsed
Exposure duration: intermittent, 10 min on/20 min off, for 90 min
  • SAR: 0.6 W/kg average over mass (brain)
  • SAR: 2.4 W/kg average over mass (brain)
  • SAR: 4.8 W/kg average over mass (brain)

Exposure 1

Main characteristics
Frequency 1,439 MHz
Type
Charakteristic
Exposure duration intermittent, 10 min on/20 min off, for 90 min
Additional info Watanabe S, Taki M, Yamanaka Y: A microwave exposure setup for the head of Sprague-Dawley rats. Proc. XXVIth General Assembly of the International Union of Radio Science (URSI), pp 863, 1999.
Modulation
Modulation type pulsed
Pulse width 6.67 ms
Repetition frequency 50 Hz
Additional info

TDMA signal for PDC (Japanese mobile phone standard) having a peak power 3-fold higher than the temporal average

Exposure setup
Exposure source
Chamber Rats in acrylic holders were placed on a carousel with their heads towards the central antenna [Watanabe et al., 1999].
Setup One anaesthetised rat was exposed together with seven dummy rats made of tissue-equivalent material.
Sham exposure A sham exposure was conducted.
Additional info After 20 min of pre-measurement, 10 min of exposure were followed by 20 min of observation, sequentially performed for all three SAR levels. The measurements in each rat were performed twice, with or without exposure.
Parameters
Measurand Value Type Method Mass Remarks
SAR 0.6 W/kg average over mass - brain -
SAR 2.4 W/kg average over mass - brain -
SAR 4.8 W/kg average over mass - brain -

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

The microcirculatory parameters investigated revealed no significant differences in values between pre and post 1439 MHz exposure of the rat brain. The data suggest that acute exposure do not change the cerebral microcirculation under the given exposure conditions, even at a level 2.4-fold higher than the local exposure limit value (2 W/kg) of the ICNIRP guidelines.

Study character:

Study funded by

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