Study type: Medical/biological study (experimental study)

Thermal aspects of biological effects of microwaves in Saccharomyces cerevisiae. med./bio.

Published in: Int J Radiat Biol Relat Stud Phys Chem Med 1985; 48 (6): 987-996

Aim of study (acc. to author)

To determine the formation of zygotes (very sensitive to changes in temperature) between two haploid strains of yeast (Saccharomyces cerevisiae) under treatment with microwaves of 9.4 and 17 GHz at power levels up to 50 and 60 mW/cm² and a SAR below 24 mW/g, or with conventional heating.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 9.4 GHz
Modulation type: CW
Exposure duration: 330 min
Exposure 2: 17 GHz
Modulation type: CW
Exposure duration: 330 min

Exposure 1

Main characteristics
Frequency 9.4 GHz
Type
Waveform
Exposure duration 330 min
Additional info near field
Modulation
Modulation type CW
Exposure setup
Exposure source
Distance between exposed object and exposure source 0.005 m
Chamber colls on Millipore filter discs (0,45µm, 2,6cm diameter) placed on solid agar in 5,5cm Petri dishes
Additional info distance horn to filter: 5mm- 30 or 40 mm
Parameters
Measurand Value Type Method Mass Remarks
SAR 21 mW/g maximum estimated - -
power density 500 W/m² maximum measured - -

Exposure 2

Main characteristics
Frequency 17 GHz
Type
Waveform
Exposure duration 330 min
Modulation
Modulation type CW
Exposure setup
Exposure source
Distance between exposed object and exposure source 0.005 m
Chamber colls on Millipore filter discs (0,45µm, 2,6cm diameter) placed on solid agar in 5,5cm Petri dishes
Parameters
Measurand Value Type Method Mass Remarks
SAR 24 mW/g maximum estimated - -
power density 600 W/m² maximum measured - -

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

It appears that these microwaves do not exhibit significant genetic effects even at power levels capable of increasing the temperature by a few degrees as revealed by zygote formation in yeast. Microwaves (9.4 GHz or 17 GHz) at a power density of 10 mW/cm² produced an increase in zygote formation equivalent to that produced by conventional heating (i.e equivalent to a rise in temperature of 0.5 or 1°C). Microwaves under these conditions had no effect on cell survival or the induction of cytolasmic "petite" mutations.

Study character:

Study funded by

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