Study type: Medical/biological study (experimental study)

Comparative effects of pulsed and continuous-wave 2.8-GHz microwaves on temporally defined behavior. med./bio.

Published in: Bioelectromagnetics 1982; 3 (2): 227-235

Aim of study (acc. to author)

To compare the effects of pulsed and continuous wave (CW) 2.8 GHz microwaves on the performance of rats maintained by a temporally defined schedule of positive reinforcement. In this DRL-schedule (differential-reinforcement-of-low-rate), delivery of food pellets was contingent upon successive lever-pressing responses that occured within a defined period.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 2.8 GHz
Modulation type: pulsed
Exposure duration: repeated exposure for 30 min/week
Exposure 2: 2.8 GHz
Modulation type: CW
Exposure duration: repeated exposure for 30 min/week

Exposure 1

Main characteristics
Frequency 2.8 GHz
Type
Polarization
Exposure duration repeated exposure for 30 min/week
Modulation
Modulation type pulsed
Pulse width 2 µs
Repetition frequency 500 Hz
Exposure setup
Exposure source
Chamber 2.44 m x 2.44 m x 2.44 m double-walled copper-screened RF-anechoic chamber lined with pyramidally shaped MW-absorbing material
Setup Animals were constrained in a sleeve holder constructed of fine plastic mesh that was suspended from a Styrofoam frame centered on the antenna's aperture approx. 6.3 wavelengths from the proximal edge of the horn. The animal's long axis was perpendicular to the propagation direction of the vertically polarised EF.
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
power density 1 mW/cm² mean measured - -
SAR 0.2 mW/g mean calculated - -
power density 5 mW/cm² mean measured - -
SAR 1.2 mW/g mean calculated - -
power density 10 mW/cm² mean measured - -
SAR 2.5 mW/g mean calculated - -
power density 15 mW/cm² mean measured - -
SAR 3.6 mW/g mean calculated - -

Exposure 2

Main characteristics
Frequency 2.8 GHz
Type
Polarization
Exposure duration repeated exposure for 30 min/week
Modulation
Modulation type CW
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
power density 1 mW/cm² mean measured - -
SAR 0.2 mW/g mean calculated - -
power density 5 mW/cm² mean measured - -
SAR 1.2 mW/g mean calculated - -
power density 10 mW/cm² mean measured - -
SAR 2.5 mW/g mean calculated - -
power density 15 mW/cm² mean measured - -
SAR 3.6 mW/g mean calculated - -

Reference articles

  • Johnson CC (1975): Recommendations for specifying EM wave irradiation conditions in bioeffects research.

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

Changes of normal performance were more pronounced after a 30 minute exposure to the pulsed wave field than to the continuous wave field. The rate of emission of appropriately timed responses declined after exposure to pulsed wave at 10 and 15 mW/cm², whereas irradiation at the same power levels to the continuous wave field did not consistently affect the rate of responding. Alteration in performance associated with microwave irradiation was not necessarily related to a general decline in responding; in some instances, increases in overall rates of responding were revealed.

Study character:

Study funded by