Study type: Medical/biological study (experimental study)

Intensity- and frequency-dependent effects of microwaves on cell growth rates med./bio.

By: Grundler W
Published in: Bioelectrochem Bioenerg 1992; 27 (3): 361-365
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Aim of study (acc. to author)

To investigate intensity- and frequency-dependent effects of microwave exposure on cell growth rate of the yeast Saccharomyces cerevisiae.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 41–42 GHz
Exposure duration: three cell cycles
Exposure 2: 41–42 GHz
Exposure duration: three cell cycles
Exposure 3: 41–42 GHz
Exposure duration: three cell cycles

Exposure 1

Main characteristics
Frequency 41–42 GHz
Type
Exposure duration three cell cycles
Exposure setup
Exposure source
  • a radiating slot 0.4 mm x 1.7 mm with quatrz needle coated with gold
Setup The cells were fixed to the öower surface of a thin transparent agar layer and rested on the quartz needle.
Parameters
Measurand Value Type Method Mass Remarks
power density 1 µW/cm² mean - - -
electric field strength 1.9 V/m mean calculated - -
SAR 40 µW/g unspecified calculated unspecified energy absorbed by agar layer
magnetic flux density 6.5 nT unspecified - - -
magnetic field strength 5.2 mA/m mean calculated - -

Exposure 2

Main characteristics
Frequency 41–42 GHz
Type
Exposure duration three cell cycles
Exposure setup
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 61 mV/m mean calculated - -
magnetic flux density 0.2 nT unspecified - - -
power density 1 nW/cm² mean - unspecified -
SAR 40 nW/g unspecified calculated - energy absorbed by agar layer
magnetic field strength 160 µA/m mean calculated - -

Exposure 3

Main characteristics
Frequency 41–42 GHz
Type
Exposure duration three cell cycles
Exposure setup
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 4.3 mV/m mean calculated - -
SAR 0.2 nW/g unspecified calculated - energy absorbed by agar layer
power density 50 nW/m² mean - unspecified -
magnetic field strength 11.5 µA/m mean calculated - -
magnetic flux density 0.015 nT unspecified - - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • during exposure

Main outcome of study (acc. to author)

The existence of a microwave effect on the growth of yeast cells was demonstrated. The mechanismen of this resonance-like effect is not clear. The resonance frequency remains the same when the external intensity applied is changed. There is a clear indication of strong negative effects on both sides of the resonance frequency (although extremely low intensities are used). For the first time a narrowing of the resonance width is observed when irradiation of lower intensities is applied. This result shows that the half-width of a resonance is intensity dependent.

Study character:

Study funded by

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