Study type: Medical/biological study (experimental study)

Thermal and physiological changes in rats exposed to CW and pulsed 2.8 GHz radiofrequency radiation in E and H orientations. med./bio.

Published in: Int J Radiat Biol 1989; 56 (6): 1033-1044

Aim of study (acc. to author)

To study the effects of microwave exposure (continuous wave and pulsed wave) on heat distribution, ECG, arterial blood pressure, and respiratory rate in anesthetized rats. The study was designed to address the issue of possible orientation differences (E orientation (long axis parallel to the electric field) and H orientation (long axis parallel to the magnetic field)), as well as pulsed versus continuous wave irradiation differences, in the same animal.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 2.8 GHz
Modulation type: CW
Exposure duration: until temperature rise from 38.5°C to 39.5 °C; once for each exposure orientation (E: 18.7 +-1.3 min; H: 7.1 +-0.4 min)
Exposure 2: 2.8 GHz
Modulation type: pulsed
Exposure duration: until temperature rise from 38.5°C to 39.5 °C ; once for each exposure orientation (E: 20.5 +-1.5 min; H: 7.5 +-0.3 min)

Exposure 1

Main characteristics
Frequency 2.8 GHz
Type
Waveform
Charakteristic
Exposure duration until temperature rise from 38.5°C to 39.5 °C; once for each exposure orientation (E: 18.7 +-1.3 min; H: 7.1 +-0.4 min)
Modulation
Modulation type CW
Exposure setup
Exposure source
Distance between exposed object and exposure source 1.5 m
Setup rats in H- and E-orientation
Parameters
Measurand Value Type Method Mass Remarks
power density 510 W/m² - cf. remarks - E-orientation
power density 730 W/m² - cf. remarks - H-orientation
SAR 14 W/kg mean cf. remarks whole body -

Exposure 2

Main characteristics
Frequency 2.8 GHz
Type
Charakteristic
Exposure duration until temperature rise from 38.5°C to 39.5 °C ; once for each exposure orientation (E: 20.5 +-1.5 min; H: 7.5 +-0.3 min)
Modulation
Modulation type pulsed
Pulse width 500 ns
Packets per second 1,000
Exposure setup
Exposure source
Distance between exposed object and exposure source 0.15 m
Setup rats in H- and E-orientation
Parameters
Measurand Value Type Method Mass Remarks
power density 510 W/m² - cf. remarks - E-orientation
power density 730 W/m² - cf. remarks - H-orientation
SAR 14 W/kg mean cf. remarks whole body -

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

The data revealed no significant difference between the thermal effects of continuous wave and pulsed wave irradiation. The findings showed significant differences between the thermal effects of E- and H-orientation exposure. H-orientation irradiation caused significantly faster colonic temperature increases and, with the exception of the tail, produced significantly greater localized heating in the anesthetized animals, and higher local SAR in rat carcasses than did E-orientation exposure.
Under all irradiation conditions, heart rate and blood pressure increased significantly during exposure and returned to baseline when irradiation was discontinued. Respiratory rate remained unchanged during exposure. There were no significant differences between the effects of E- and H-orientation exposure, or between continuous wave and pulsed wave exposure, upon heart rate, blood pressure, and respiratory rate.

Study character:

Study funded by

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