Study type: Medical/biological study (experimental study)

Effects of modulated VHF fields on the central nervous system. med./bio.

Published in: Ann N Y Acad Sci 1975; 247: 74-81

Aim of study (acc. to author)

To investigate the effects of 147 MHz radiofrequency irradiation at various AM modulation on the calcium efflux from chicken brain tissue in vitro.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 147 MHz
Modulation type: AM

Exposure 1

Main characteristics
Frequency 147 MHz
Type
Waveform
Modulation
Modulation type AM
Modulation frequency 0–35 Hz
Modulation depth 90 %
Additional info

Modulation frequencies of 0.5, 3, 6, 9, 11, 16, 20 and 25 Hz and an unmodulated carrier wave were also used.

Exposure setup
Exposure source
Setup two triangular alminium plates / 4100 cm²
Additional info chick brains put into test tubes
Parameters
Measurand Value Type Method Mass Remarks
power density 10 W/m² unspecified measured - or 20 W/m²

Reference articles

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

The 147 MHz VHF filed was AM modulated at 0.5, 3, 6, 9, 11, 16, 20, 25, and 35 Hz. Unmodulated exposure and fields modulated at 0.5 and 3 Hz as well as 35 Hz modulation did not significantly alter the calcium efflux. Whereas a progressive increase of calcium efflux at modulation frequencies from 6 to 16 Hz were observed. At 20 Hz AM modulation the calcium efflux were comparable to the one at 6 Hz. Results obtained at 25 Hz modulation were not statisically significant.
Data obtained from an additional experiment with NaCN poisoned brain tissue did not differ and suggests that the calcium efflux is independent of other metabolic activities.
Finally, a preliminary experiment with chicken skeletal muscle did not indicate any major differences.

Study character:

Study funded by

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