Study type: Medical/biological study (experimental study, theoretical study)

Comparative thermoregulatory response to passive heat loading by exposure to radiofrequency radiation med./bio.

By: Gordon CJ, Ali JS
Published in: Comp Biochem Physiol A Comp Physiol 1987; 88 (1): 107-112
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Aim of study (acc. to author)

1) To evaluate the effect of 600 MHz radiofrequency irradiation on colonic and tail skin temperature of the rat at ambient temperatures of 20, 28 or 35°C. 2) To evaluate the utility of an allometric function to predict the effect of ambient temperature on the SAR needed to elevate the body temperature of various laboratory mammals. Data from this study were combined with data from earlier studies to assess the impact of varying ambient temperatures on the thermogenic effect of radiofrequency irradiation in different species.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 600 MHz
Exposure duration: 90 min
  • SAR: 6 W/kg maximum (0 - 6 W/Kg)

Exposure 1

Main characteristics
Frequency 600 MHz
Type
Exposure duration 90 min
Exposure setup
Exposure source
Setup rats placed in 23.5 cm X 16.5 cm X 14 cm cage inside the waveguide
Parameters
Measurand Value Type Method Mass Remarks
SAR 6 W/kg maximum - - 0 - 6 W/Kg

Reference articles

  • Ali JS et al. (1987): Control of energy absorption rate in transmission line radiofrequency exposure systems
  • Gordon CJ et al. (1986): Temperature regulation in the mouse and hamster exposed to microwaves in hot environments
  • Gordon CJ et al. (1986): Body temperature in the mouse, hamster, and rat exposed to radiofrequency radiation: an interspecies comparison

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

1) The SAR needed to elevate colonic and tail skin temperature decreased with increasing ambient temperature. For example, a 0.5°C elevation in colonic temperature occurred at SARs of 4.3, 0.9 and 0.5 W/kg when ambient temperature was maintained at 20, 28 and 35°C, respectively.
2) In species ranging in mass from 0.02 to 3.2 kg, a double logarithmic plot of body mass versus SAR needed to elevate colonic temperature by 0.5°C was linear and inverse. The highly correlated allometric relationship shows that, as body mass decreases, the relative impact of ambient temperature on the thermogenic effect of radiofrequency irradiation increases.

Study character:

Study funded by