Study type: Medical/biological study (experimental study)

Thermoregulatory responses of febrile monkeys during microwave exposure med./bio.

By: Adair ER, Adams BW, Kelleher SA, Streett JW
Published in: Ann N Y Acad Sci 1997; 813: 497-507
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Aim of study (acc. to author)

To examine the question of increased vulnerability to the thermalizing effects of microwave exposure during febrile illness.

Background/further details

In a controlled ambient temperature of 26°C, autonomic mechanisms of heat production and heat loss were measured in febrile monkeys during exposures to continuous wave microwave fields at different phases of the fever cycle.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 450 MHz
Modulation type: CW
Exposure duration: continuous for 30 min
Exposure 2: 2,450 MHz
Modulation type: CW
Exposure duration: continuous for 30 min

Exposure 1

Main characteristics
Frequency 450 MHz
Type
Charakteristic
Exposure duration continuous for 30 min
Modulation
Modulation type CW
Exposure setup
Exposure source
Setup Monkeys were lightly restrained in a Plexiglas chair inside a ventilated Styrofoam test compartment.
Sham exposure A sham exposure was conducted.
Additional info After 90 min of equilibration, prostaglandin E1 (PGE) was injected into the PO/AH to initiate a febrile episode. At 5, 35, or 65 min later, the monkey was exposed to a single power density for 30 min at 26°C. As controls, sessions were conducted at each frequency with PGE alone, MW alone, and no exposure at all. In addition, a few experiments were performed at 32°C at 450 MHz and 5 mW/cm².
Parameters
Measurand Value Type Method Mass Remarks
power density 5 mW/cm² - measured - -
SAR 2.06 W/kg - measured whole body -
power density 8 mW/cm² - measured - -
SAR 3.3 W/kg - measured whole body -
Measurement and calculation details

Field uniformity was determined in the area occupied by the animal using a broadband isotropic E-field probe. Whole-body SAR, based on temperature increments in saline-filled Styrofoam models, was 0.413 or 0.165 W/kg per mW/cm² at 450 or 2450 MHz, respectively [Adair et al., 1992].

Exposure 2

Main characteristics
Frequency 2,450 MHz
Type
Charakteristic
Exposure duration continuous for 30 min
Modulation
Modulation type CW
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
power density 10 mW/cm² - measured - -
SAR 1.65 W/kg - measured whole body -
power density 20 mW/cm² - measured - -
SAR 3.3 W/kg - measured whole body -

Reference articles

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • before exposure
  • during exposure
  • after exposure

Main outcome of study (acc. to author)

Microwave energy absorbed during a febrile episode spares endogenous energy production, but may augment the fever if deposited deep in the body, as is the case during irradiation at the resonant frequency (450 MHz). The fever may also be exacerbated if the microwave exposure occurs late in the febrile episode, a condition that may put an organism at some risk, especially if the field strength exceeds safety guidelines.

Study character:

Study funded by

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