Study type: Medical/biological study (experimental study)

Avoidance by rats of illumination with low power nonionizing electromagnetic energy med./bio.

By: Frey AH, Feld SR
Published in: J Comp Physiol Psychol 1975; 89 (2): 183-188
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Aim of study (acc. to editor)

To study whether rats might perceive and avoid pulsed microwave energy illumination in a shuttle box situation and whether microwave energy has reliable motivational properties at low average power densities.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 1.2 GHz
Modulation type: pulsed
Exposure duration: 90 min
  • power density: 9 W/m² mean (300 mW/cm² peak value; measured in the unshielded half of box B)
  • power density: 4 W/m² mean (133 mW/cm² peak value; measured in the unshielded half of box A)
Exposure 2: 1.2 GHz
Modulation type: pulsed
Exposure duration: four 30 min exposure session
Exposure 3: 1.2 GHz
Modulation type: CW
Exposure duration: four 30 min exposure session

Exposure 1

Main characteristics
Frequency 1.2 GHz
Charakteristic
Polarization
Exposure duration 90 min
Additional info Experiment 1 Horizontally polarized
Modulation
Modulation type pulsed
Pulse width 30 µs
Repetition frequency 100 Hz
Exposure setup
Exposure source
Distance between exposed object and exposure source 0.06 m
Chamber Eccosorb FR-340 RF anechoic chamber
Setup Animals kept in either one of the shuttle boxes mounted on wooden tables.
Additional info Two acrylic shuttle boxes; each box was 22 cm x 21 cm x 30 cm with their respective right and left halves shielded; A half way dipole antenna located 6 cm on the top of the boxes.
Parameters
Measurand Value Type Method Mass Remarks
power density 9 W/m² mean measured - 300 mW/cm² peak value; measured in the unshielded half of box B
power density 4 W/m² mean measured - 133 mW/cm² peak value; measured in the unshielded half of box A

Exposure 2

Main characteristics
Frequency 1.2 GHz
Charakteristic
Polarization
Exposure duration four 30 min exposure session
Additional info Experiment 2 Horizontally polarized
Modulation
Modulation type pulsed
Pulse width 500 µs
Rise time 1 µs
Repetition frequency 1,000 Hz
Additional info

Exponential decay of 1/3 of the peak amplitude.
Exposure setup
Exposure source
Distance between exposed object and exposure source 0.06 m
Parameters
Measurand Value Type Method Mass Remarks
power density 2 W/m² mean measured - 2.1 mW/cm² peak value

Exposure 3

Main characteristics
Frequency 1.2 GHz
Charakteristic
Polarization
Exposure duration four 30 min exposure session
Additional info Experiment 2 Horizontally polarized
Modulation
Modulation type CW
Exposure setup
Exposure source
Distance between exposed object and exposure source 0.06 m
Parameters
Measurand Value Type Method Mass Remarks
power density 24 W/m² mean measured - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • during exposure

Main outcome of study (acc. to author)

The rats tend to avoid low-intensity pulse-modulated electromagnetic energy in the free field. The data suggest that less than 130 mW/cm² peak power density and less than 0.4 mW/cm² average power density are needed to produce aversion. Energy at 2.1 mW/cm² peak and 0.2 mW/cm² average power density is also avoided and may be approaching a perceptual or motivational threshold. Continuous illumination did not appear to influence the shuttle box behaviour.

Study character:

Study funded by