Study type: Medical/biological study (experimental study)

Electroencephalographic and morphological studies on the effect of microwaves on the central nervous system med./bio.

Published in: Acta Physiol Pol 1967; 18 (4): 517-532
Journal partially peer-reviewed/unclear

Aim of study (acc. to author)

A series of EEG and morphological investigations was carried out to elucidate the influence of microwave exposure on CNS. The difference in the action of a pulsed and continuous electromagnetic field was investigated.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 3 GHz
Modulation type: pulsed
Exposure duration: 3 h/day for 60 days
10 cm bands with pulse modulation
Exposure 2: 3 GHz
Modulation type: CW
Exposure duration: 3 h/day for 60 days
10 cm band with continuous wave
Exposure 3: 10 GHz
Modulation type: pulsed
Exposure duration: 3 h/day for 60 days
Exposure 4: 3 GHz
Modulation type: pulsed, CW
Exposure duration: 5-30 mW/cm² increased 5 mW/cm² every 15 min, i.e. 6 x 15 min
  • power density: 300 W/m² (5-30mW/cm² increased 5mW/cm² ever 15min)
Exposure 5: 10 GHz
Modulation type: pulsed
Exposure duration: 5-10 mW/cm² increased 5 mW/cm² every 15 min, i.e. 30 min
  • power density: 100 W/m² (5-10mW/cm² increased 5mW/cm² ever 15min)

Exposure 1

Main characteristics
Frequency 3 GHz
Type
Exposure duration 3 h/day for 60 days
Additional info 10 cm bands with pulse modulation
Additional info 10cm-band
Modulation
Modulation type pulsed
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
power density 50 W/m² - - - -

Exposure 2

Main characteristics
Frequency 3 GHz
Type
Exposure duration 3 h/day for 60 days
Additional info 10 cm band with continuous wave
Additional info 10cm-band
Modulation
Modulation type CW
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
power density 50 W/m² - - - -

Exposure 3

Main characteristics
Frequency 10 GHz
Exposure duration 3 h/day for 60 days
Additional info 3 cm band with pulse modulation
Additional info 3 cm-band
Modulation
Modulation type pulsed
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
power density 50 W/m² - - - -

Exposure 4

Main characteristics
Frequency 3 GHz
Type
Exposure duration 5-30 mW/cm² increased 5 mW/cm² every 15 min, i.e. 6 x 15 min
Additional info 10cm-band
Modulation
Modulation type pulsed, CW
Additional info

pulsed and continuous

Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
power density 300 W/m² - - - 5-30mW/cm² increased 5mW/cm² ever 15min

Exposure 5

Main characteristics
Frequency 10 GHz
Type
Exposure duration 5-10 mW/cm² increased 5 mW/cm² every 15 min, i.e. 30 min
Additional info 3cm-band
Modulation
Modulation type pulsed
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
power density 100 W/m² - - - 5-10mW/cm² increased 5mW/cm² ever 15min

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

Chronic exposure with microwaves within the 10 cm band (7 mW/cm² power density), which do not raise the temperature, produces both functional and morphological changes, their intensity being greater when pulse modulation and not continuous modulation is applied.
The absence of a major effect of a single exposure to microwaves (5-7 mW/cm² power density) and simultaneous intensification of the changes as the period of exposure is prolonged, point to the possibility of cumulation of the doses applied. The negative effect of a single exposure to microwaves of equal length depends on the power density and kind of modulation applied.
The changes revealed under pulse modulation seem to be independent of the thermic effect. On the contrary, the character of the changes in the case of application of continuous modulation and the temperature rise observed seem to indicate a predominance of the thermic effect. The absence of noticeable functional and morphological changes upon exposure to 3 cm microwaves is evidence of the dependence of the effect on wavelength. This in turn seems to be related with the absorption of energy by the surface tissues.

Study character:

Study funded by