Study type: Medical/biological study (experimental study)

Radiofrequency-radiation exposure does not induce detectable leakage of albumin across the blood-brain barrier. med./bio.

Published in: Radiat Res 2009; 171 (5): 615-621

Aim of study (acc. to author)

To determine whether the blood-brain barrier is altered in rats (n=28-46 per group) exposed in a TEM cell to 915 MHz energy at parameters similar to those in the Lund University studies (see "related studies" of the authors Salford, Persson and Brun).

Background/further details

Although the authors used the same type of exposure system, immunohistochemical techniques, and tissue analysis procedures as used in the Swedish study, there were a number of differences in the design of this study (e.g. number of animals, exposure duration, male rats only, SAR value).
Positive controls were performed by catheter implantation and urea infusion and by radiofrequency (2060 MHz) heating to 43°C.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 915 MHz
Modulation type: CW
Exposure duration: continuous for 30 min
  • SAR: 0.002 W/kg minimum (whole body) (0.002, 0.02, 0.2, 2.0, 20 W/kg)
  • SAR: 20 W/kg maximum (whole body)
Exposure 2: 915 MHz
Modulation type: pulsed
Exposure duration: continuous for 30 min
  • SAR: 0.0018 W/kg minimum (whole body) (0.0018, 0.018, 0.18 W/kg)
  • SAR: 0.18 W/kg maximum (whole body)
Exposure 3: 915 MHz
Modulation type: pulsed
Exposure duration: continuous for 30 min
  • SAR: 0.0025 W/kg minimum (whole body) (0.0025, 0.025, 0.248, 2.48 W/kg)
  • SAR: 2.48 W/kg maximum (whole body)

Exposure 1

Main characteristics
Frequency 915 MHz
Type
Exposure duration continuous for 30 min
Modulation
Modulation type CW
Exposure setup
Exposure source
Setup animals held in 14 cm x 14 cm x 6 cm Plexiglas cages inside the TEM cell
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
SAR 0.002 W/kg minimum measured and calculated whole body 0.002, 0.02, 0.2, 2.0, 20 W/kg
SAR 20 W/kg maximum measured and calculated whole body -

Exposure 2

Main characteristics
Frequency 915 MHz
Type
Exposure duration continuous for 30 min
Modulation
Modulation type pulsed
Pulse width 0.57 ms
Duty cycle 0.91 %
Repetition frequency 16 Hz
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
SAR 0.0018 W/kg minimum measured and calculated whole body 0.0018, 0.018, 0.18 W/kg
SAR 0.18 W/kg maximum measured and calculated whole body -

Exposure 3

Main characteristics
Frequency 915 MHz
Type
Exposure duration continuous for 30 min
Modulation
Modulation type pulsed
Pulse width 0.57 ms
Duty cycle 12.4 %
Repetition frequency 217 Hz
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
SAR 0.0025 W/kg minimum measured and calculated whole body 0.0025, 0.025, 0.248, 2.48 W/kg
SAR 2.48 W/kg maximum measured and calculated whole body -

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 data revealed no significant increase in albumin extravasation in any of the exposed animals compared to the sham exposed or cage control animals. Using a very similar experimental approach as the Swedish group, the authors have been unable to confirm their results.

Study character:

Study funded by

Related articles