Study type: Medical/biological study (experimental study)

Blood-brain barrier permeation in the rat during exposure to low-power 1.7-GHz microwave radiation med./bio.

By: Ward TR, Ali JS
Published in: Bioelectromagnetics 1985; 6 (2): 131-143
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Aim of study (acc. to author)

Attempt to reproduce previously reported findings of increased permeability of blood-brain barrier at low power levels <10mW/cm² in rats.

Background/further details

Only the head of the animal was exposed, while in the previous study (see publication 72) the whole body was exposed.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 1.7 GHz
Modulation type: pulsed
Exposure duration: continuous for 30 min
  • SAR: 100 µW/g mean (partial body) (in the head; peak SAR: 200 W/kg)
Exposure 2: 1.7 GHz
Modulation type: CW
Exposure duration: continuous for 30 min
  • SAR: 100 µW/g mean (partial body) (in the haed)

Exposure 1

Main characteristics
Frequency 1.7 GHz
Type
Waveform
Charakteristic
  • guided field
Polarization
Exposure duration continuous for 30 min
Modulation
Modulation type pulsed
Pulse width 500 ns
Packets per second 1,000
Exposure setup
Exposure source
Chamber TE10, foamed polystyrene platform
Setup The rat was exposed by placing its head in a hole in the side of the waveguide which was placed in a screened wooden box.
Parameters
Measurand Value Type Method Mass Remarks
SAR 100 µW/g mean determined by power loss partial body in the head; peak SAR: 200 W/kg

Exposure 2

Main characteristics
Frequency 1.7 GHz
Type
Waveform
Charakteristic
  • guided field
Polarization
Exposure duration continuous for 30 min
Modulation
Modulation type CW
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
SAR 100 µW/g mean determined by power loss partial body in the haed

Reference articles

  • Ward TR et al. (1982): Measurement of blood-brain barrier permeation in rats during exposure to 2450-MHz microwaves

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

In the earlier study pulsed and CW (continuous wave) microwave radiation increased permeation of labeled compounds through the blood-brain barrier. In this study no changes in permeability of blood-brain barrier in all brain areas analysed were found. Microwave exposure caused small but significant temperature increases in 2 out of 8 brain areas.

Study character:

Study funded by

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