Study type: Medical/biological study (experimental study)

Thermal and physiologic responses to 1200-MHz radiofrequency radiation: differences between exposure in E and H orientation. med./bio.

Published in: Proc Soc Exp Biol Med 1990; 194 (4): 358-363

Aim of study (acc. to author)

To determine the effects of 1200 MHz irradiation on patterns of heat disposition, heart rate, blood pressure, and respiratory rate in anesthetized rats in E orientation (long axis of body parallel to electric field) and H orientation (long axis of body parallel to magnetic field).

Endpoint

Exposure

Exposure Parameters
Exposure 1: 1.2 GHz
Modulation type: CW
Exposure duration: until the temperature had risen from 38.5° to 39.5°
Exposure 2: 1.2 GHz
Modulation type: CW
Exposure duration: until the temperature had risen from 38.5° to 39.5°

General information

*The exposure was discontinued when the colonic temperature increased to 39.5°C and it was initiated again when the temperature returned to 38.5°C. This procedure was continued for 3 cycles

Exposure 1

Main characteristics
Frequency 1.2 GHz
Type
Charakteristic
Polarization
Exposure duration until the temperature had risen from 38.5° to 39.5°
Additional info Animals were exposed in E orientation (long body axis of the animals parallel to the electric field)
Modulation
Modulation type CW
Exposure setup
Exposure source
Distance between exposed object and exposure source 1.7 m
Chamber Eccosorb RF-shield anechoic chamber
Setup Animals placed on a holder which consisted of seven 0.5 cm (outside diameter) Plexiglas rods mounted in a semicircular pattern on 4 cm x 6 cm Plexiglas plates (0.5 cm thick).
Parameters
Measurand Value Type Method Mass Remarks
power density 20 mW/cm² unspecified measured - -
SAR 8 W/kg mean calculated whole body ± 0.3 W/kg

Exposure 2

Main characteristics
Frequency 1.2 GHz
Type
Charakteristic
Polarization
Exposure duration until the temperature had risen from 38.5° to 39.5°
Additional info Animals were exposed in H orientation (long body axis of the animals parallel to the electric field)
Modulation
Modulation type CW
Exposure setup
Exposure source
Distance between exposed object and exposure source 1.7 m
Parameters
Measurand Value Type Method Mass Remarks
power density 45 mW/cm² - measured - -
SAR 8.1 W/kg mean calculated whole body ± 0.4 W/kg

Reference articles

  • Allen SJ et al. (1979): Calorimetric measurements of microwave energy absorption by mice after simultaneous exposure of 18 animals.

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

Exposure in E-orientation resulted in greater colonic, tympanic, left subcutaneous (side toward antenna), and tail heating. The findings indicated a more uniform distribution of heat than that which occurred in previous experiments of 2450-MHz irradiation in E- and H-orientation (publication 2239). A lack of significant differences in blood pressure and heart rate responses between exposures in the two orientations in this investigation suggest that greater peripheral heating, as observed in the earlier study of 2450 MHz, is necessary for these differences to occur.

Study character:

Study funded by

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