Study type: Medical/biological study (experimental study)

Microwave effects on plasmid DNA. med./bio.

Published in: Radiat Res 1987; 110 (2): 219-231

Aim of study (acc. to author)

To study whether exposure of plasmid DNA to nonthermal doses of microwaves causes any detectable damage to the molecules.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 2–8.75 GHz
Modulation type: CW
Exposure duration: 20 min
Exposure 2: 10 kHz
Exposure duration: n/a

Exposure 1

Main characteristics
Frequency 2–8.75 GHz
Type
Waveform
Charakteristic
Exposure duration 20 min
Additional info 2,00; 3,45; 7,64 GHz minimum absorption 2,55; 8,75 GHz resonant absorption
Modulation
Modulation type CW
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
SAR 10 mW/g maximum calculated - -
electric field strength 136 V/m maximum measured - on surface

Exposure 2

Main characteristics
Frequency 10 kHz
Type
Waveform
Exposure duration n/a
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 45 V/cm maximum cf. remarks - at uncoated antenna surface
SAR 10 mW/g maximum cf. remarks cf. remarks with max surface field of 136 V/m
electric field strength 136 V/m maximum cf. remarks - max surface field

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:

Main outcome of study (acc. to author)

The results indicate that the interaction of microwave with purified DNA in the presence of a small amount of copper can lead to single and double-strand breaks. Contact with the copper antenna produces slight but noticeable damage to isolated plasmid-DNA. Microwaves significantly increase the damage. The effect of microwaves is to increase the number of single- and double-strand breaks. Effects on DNA were observed throughout the frequency range studied and could not be correlated with resonant frequencies. The damage is linearly related to both the power applied and the duration of the exposure to microwaves. Temperature increase seems to play no role in producing the breaks.

Study character:

Study funded by

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