Study type: Medical/biological study (experimental study)

Modification of the repeated acquisition of response sequences in rats by low-level microwave exposure. med./bio.

Published in: Bioelectromagnetics 1980; 1 (1): 89-99

Aim of study (acc. to author)

To investigate the effects of low-power microwave fields on the acquisition of behavior.

Background/further details

Rats were trained to acquire a different four-member chain of responses each session. They were maintained by food reinforcement and subsequently exposed to low levels of microwave irradiation for assessment of behavioral effects. The reinforcement contingencies were arranged so that each correct response advanced the rat closer to and eventually produced reinforcement. Each error or timeout response delayed reinforcement delivery.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 2.8 GHz
Modulation type: pulsed
Exposure duration: continuous for 30 min
Exposure 2: 2.8 GHz
Modulation type: pulsed
Exposure duration: continuous for 30 min
Exposure 3: 2.8 GHz
Modulation type: pulsed
Exposure duration: continuous for 30 min
Exposure 4: 2.8 GHz
Modulation type: pulsed
Exposure duration: continuous for 30 min
Exposure 5: 2.8 GHz
Modulation type: pulsed
Exposure duration: continuous for 30 min

Exposure 1

Main characteristics
Frequency 2.8 GHz
Type
Waveform
Charakteristic
Polarization
Exposure duration continuous for 30 min
Additional info vertically polarized
Modulation
Modulation type pulsed
Pulse width 2 µs
Repetition frequency 500 Hz
Exposure setup
Exposure source
Chamber 2.44 x 2.44 x 2.44 m; lined with MW absorbing material; exterior surfaces shielded with double wallet copper screening.
Setup Animals were exposed while being restrained in a plastic mesh sleeve holder which was suspended from a styrofoam frame.
Additional info Omnidirectional pole lever, mounted from the ceiling and centered 4 cm from the intelligence panel. Electric field was perpendicular to the long axis of the animal`s body.
Parameters
Measurand Value Type Method Mass Remarks
power density 250 mW/cm² peak value measured - 0.25 mW/cm² corresponding average power density

Exposure 2

Main characteristics
Frequency 2.8 GHz
Type
Waveform
Charakteristic
Polarization
Exposure duration continuous for 30 min
Additional info vertically polarized
Modulation
Modulation type pulsed
Pulse width 2 µs
Repetition frequency 500 Hz
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
power density 500 mW/cm² peak value measured - 0.5 mW/cm² corresponding average power density

Exposure 3

Main characteristics
Frequency 2.8 GHz
Type
Waveform
Charakteristic
Polarization
Exposure duration continuous for 30 min
Additional info vertically polarized
Modulation
Modulation type pulsed
Pulse width 2 µs
Repetition frequency 500 Hz
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
power density 1 W/cm² peak value measured - 1 mW/cm² corresponding average power density

Exposure 4

Main characteristics
Frequency 2.8 GHz
Type
Waveform
Charakteristic
Polarization
Exposure duration continuous for 30 min
Additional info vertically polarized
Modulation
Modulation type pulsed
Pulse width 2 µs
Repetition frequency 500 Hz
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
power density 5 W/cm² peak value measured - 5 mW/cm² corresponding average power density

Exposure 5

Main characteristics
Frequency 2.8 GHz
Type
Waveform
Charakteristic
Polarization
Exposure duration continuous for 30 min
Additional info vertically polarized
Modulation
Modulation type pulsed
Pulse width 2 µs
Repetition frequency 500 Hz
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
power density 10 W/cm² peak value measured - 10 mW/cm² corresponding average power density

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

The exposure to microwave irradiation disrupted the pattern of acquisition. Exposure with a power density of 10 mW/cm² produced consistent alterations in behavior. Exposure at 5 mW/cm² produced alterations in 50% of the test sessions. The alterations were characterized by an increase in total error responses, as well as an elevation in pausing between responses. The data of exposures at 0.25, 0.5, and 1 mW/cm² power densities were generally within the control range.

Study character:

Study funded by