Study type: Medical/biological study (experimental study)

Effects of modulated RF energy on the EEG of mammalian brains. Effects of acute and chronic irradiations med./bio.

By: Takashima S, Onaral B, Schwan HP
Published in: Radiat Environ Biophys 1979; 16 (1): 15-27
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Aim of study (acc. to author)

To investigate the effects of modulated radiofrequency fields on mammalian EEGs using acute and chronic irradiations at non-thermal level.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 1–30 MHz
Modulation type: AM
Exposure duration: 2 to 3 h (acute exposure)
Exposure 2: 1–10 MHz
Modulation type: AM
Exposure duration: 2 h/day for 6 weeks (4-6 weeks for chronic exposures)

Exposure 1

Main characteristics
Frequency 1–30 MHz
Type
Exposure duration 2 to 3 h (acute exposure)
Modulation
Modulation type AM
Modulation frequency 60 Hz
Modulation depth 95 %
Exposure setup
Exposure source
  • aluminium plates, 30x30cm distance 20cm
Distance between exposed object and exposure source 0.2 m
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 500 V/m minimum unspecified - 1 kV/m max value.

Exposure 2

Main characteristics
Frequency 1–10 MHz
Type
Exposure duration 2 h/day for 6 weeks (4-6 weeks for chronic exposures)
Modulation
Modulation type AM
Modulation frequency 14–16 Hz
Modulation depth 95 %
Exposure setup
Exposure source
  • aluminium plates, 30x30cm distance 20cm
Distance between exposed object and exposure source 0.2 m
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 500 V/m unspecified unspecified - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

With continued use of intracranial metal electrodes, modulated radiofrequency fields caused a change in EEG patterns by enhancing the low frequency components and decreasing high frequency activities. On the other hand, acute exposures did not produce noticeable changes in the EEG at the level of 0.5-1 kV/M (1-30 MHz, 60 Hz modulation) as long as the use of intracranial electrodes was avoided. This observation indicates that intracranial electrodes are capable of distorting the electric field and cause serious artifacts.
The chronic irradiation was designed so that the effect of electrodes was minimized. Prolonged and repeated exposures to amplitude modulated radiofrequency fields at the level of 500 V/M was found to cause noticeable changes in power spectra, i.e. appearance of low frequency components and reduction of high frequency activities.

Study character:

Study funded by

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