Study type: Medical/biological study (experimental study)

Permeability of the blood-brain barrier induced by 915 MHz electromagnetic radiation, continuous wave and modulated at 8, 16, 50 and 200 Hz. med./bio.

Published in: Bioelectrochem Bioenerg 1993; 30: 293-301

Aim of study (acc. to author)

To study the permeability of blood-brain barrier to endogenous albumin and fibrinogen during exposure to microwaves of 915 MHz as continuous wave and pulse-modulated at the various repetition rates (8, 16, 50, and 200 Hz).

Endpoint

Exposure

Exposure Parameters
Exposure 1: 915 MHz
Modulation type: CW
Exposure duration: not specified
  • power: 3 W peak value (0.2-3 W)
  • SAR: 0.33 W/kg (at 0.2 W)
Exposure 2: 915 MHz
Modulation type: pulsed
Exposure duration: not specified

Exposure 1

Main characteristics
Frequency 915 MHz
Type
Charakteristic
  • guided field
Exposure duration not specified
Modulation
Modulation type CW
Exposure setup
Exposure source
Chamber The TEM cell was enclosed in a well ventilated wooden box supporting the outer conductor made of brass-net and the central plate, or septum, constructed of aluminium and held up by Teflon braces.
Additional info The rats were not anaesthetized during the exposure.
Parameters
Measurand Value Type Method Mass Remarks
power 3 W peak value - - 0.2-3 W
SAR 0.33 W/kg - calculated - at 0.2 W

Exposure 2

Main characteristics
Frequency 915 MHz
Type
Charakteristic
  • guided field
Exposure duration not specified
Modulation
Modulation type pulsed
Additional info

Pulses had a width of 0.57 ms at frequencies of 8, 16 or 200 Hz and of 4 ms at 50 Hz.

Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
power 20 W peak value - - 1-20 W
SAR 3.3 W/kg - calculated - 10 W/pulse at 50 Hz pulse frequency
SAR 0.4 W/kg - calculated - 2 W/pulse at 200 Hz pulse frequency

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 results reveal that both continuous and low pulsed microwaves are able to open up the blood-brain barrier for albumin passage. However, there is no significant difference between continuous wave and pulsed 915 MHz microwaves in this respect.

Study character:

Study funded by

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