Study type: Medical/biological study (experimental study)

Fixed interval behavior of rats to microwaves at low power densities. med./bio.

Published in: Radio Sci 1977; 12: 273-277

Aim of study (acc. to author)

To explore behavioral effects during exposure of rats to microwave irradiation at low power densities.

Background/further details

Furthermore, the relation between response rate and power densitiy was investigated by using a complex schedule of reinforcement that generates both low- and high-response rates. Lever pressing was reinforced by food pellets on a fixed-interval schedule and produced for initial values without irradiation (baseline measurement) high rates of responding in two rats and low rates of responding in the other two rats.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 2.45 GHz
Modulation type: AM
Exposure duration: 60 min
Exposure 2: 2.45 GHz
Modulation type: AM
Exposure duration: 60 min
Exposure 3: 2.45 GHz
Modulation type: AM
Exposure duration: 60 min

Exposure 1

Main characteristics
Frequency 2.45 GHz
Type
Waveform
Exposure duration 60 min
Modulation
Modulation type AM
Modulation frequency 120 Hz
Modulation depth 100 %
Exposure setup
Exposure source
Distance between exposed object and exposure source 1.497 m
Exposure room response chamber of styrofoam 24x30x30 cm
Parameters
Measurand Value Type Method Mass Remarks
power density 88 W/m² mean measured - -

Exposure 2

Main characteristics
Frequency 2.45 GHz
Type
Waveform
Exposure duration 60 min
Modulation
Modulation type AM
Modulation frequency 120 Hz
Modulation depth 100 %
Exposure setup
Exposure source
Distance between exposed object and exposure source 1.497 m
Exposure room response chamber of styrofoam 24x30x30 cm
Parameters
Measurand Value Type Method Mass Remarks
power density 184 W/m² mean measured - -

Exposure 3

Main characteristics
Frequency 2.45 GHz
Type
Waveform
Exposure duration 60 min
Modulation
Modulation type AM
Modulation frequency 120 Hz
Modulation depth 100 %
Exposure setup
Exposure source
Distance between exposed object and exposure source 1.497 m
Exposure room response chamber of styrofoam 24x30x30 cm
Parameters
Measurand Value Type Method Mass Remarks
power density 375 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)

Exposure at 37.5 mW/cm² disrupted the lever response in the two animals that responded at high rates during baseline measures. Exposure at the two lower power densities had no observable effect on the rate of responding.
For the two animals that responded at low rates, no effects on rate of lever pressing were observed at any of the power densities. However, ambulatory activity of all animals decreased during exposure at 18.4 and 37.5 mW/cm². This decrease was associated with a tendency of the animals to remain in areas of the response chamber with lower power densities.
The data are believed to be due to an interaction between higher metabolic rates in the more frequently responding rats and exogenous heating by microwave irradiation.

Study character:

Study funded by