Study type: Medical/biological study (experimental study)

Chromosome DNA as a target of resonant interaction between Escherichia coli cells and low-intensity millimeter waves med./bio.

By: Belyaev IY, Alipov YD, Shcheglov VS
Published in: Electro Magnetobiol 1992; 11 (2): 97-108
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Aim of study (acc. to author)

To study the influence of millimeter waves on the process of the genome conformational state repair in E. coli (with and without preceding exposure to X-rays).
To determine the sign of effective polarization (linear, left-handed circular, and right-handed circular) and parameters of resonances in the 51.62-51.84 GHz band, the effect of differently polarized millimeter waves on the genome conformational state of intact cells and cells exposed to X-rays at a dose of 20 Gy was studied (see "Background/further details"). Other radiation doses of 0.01-3 Gy were also conducted to determine the minimal effective dose.

Background/further details

In a previous study (see publication 10177), linearly polarized microwaves in two frequency bands (41.25-41.50 GHz and 51.62-51.84 GHz) suppressed repair of genome conformational state in cells exposed to 20-30 Gy of X-rays and in both bands, the effect was frequency dependent with resonance frequencies of f = 41.32 GHz and f = 51.76 GHz. In subsequent studies (publication 15590) it was established that right- and left-handed polarized electromagnetic irradiation have different efficiency at resonance frequencies.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 51.62–51.84 GHz
Exposure duration: continuous for 10 min after X-ray irradiation
  • SAR: 6 µW/g spatial average (cf. remarks) (at 1 µW/cm²)
  • power density: 100 µW/cm² spatial average
Exposure 2: 51.76 GHz
Exposure duration: continuous for 5 min after X-ray irradiation
  • SAR: 6 µW/g spatial average (cf. remarks) (at 1 µW/cm²)
  • power density: 100 µW/cm² spatial average
Exposure 3: 51.76 GHz
Exposure duration: continuous for 5 min
  • SAR: 6 µW/g spatial average (cf. remarks) (at 1 µW/cm²)
  • power density: 100 µW/cm² spatial average
Exposure 4: 51.68–51.85 GHz
Exposure duration: continuous for 5 min
  • SAR: 6 µW/g spatial average (cf. remarks) (at 1 µW/cm²)
  • power density: 100 µW/cm² spatial average

General information

for further information on the exposure setup see: Belyaev, I. Ya., Shcheglov, V. S., and Alipov, Ye. D. "Selection rules on helicity during discrete transitions of the genome conformational state in intact and X-rayed cells of E. coli in millimeter rage of electromagnetic field." In: Charge and Field Effects in Biosystems-3 (M. J. Allen, S. F. Cleary, A. E. Sowers, and D. D. Shillady, eds.), Birkhäuser, Boston, 1992, pp. 115-126 cells were treated in four groups: i) control ii) X-ray irradiation iii) EMF iv) X-rays + EMF

Exposure 1

Main characteristics
Frequency 51.62–51.84 GHz
Type
Exposure duration continuous for 10 min after X-ray irradiation
Exposure setup
Exposure source
  • not specified
Additional info linear, left-handed circular and right-handed circular polarized electromagnetic field used
Parameters
Measurand Value Type Method Mass Remarks
SAR 6 µW/g spatial average measured cf. remarks at 1 µW/cm²
power density 100 µW/cm² spatial average measured - -

Exposure 2

Main characteristics
Frequency 51.76 GHz
Type
Polarization
  • circular
Exposure duration continuous for 5 min after X-ray irradiation
Exposure setup
Exposure source
Additional info left-handed circular and right-handed circular polarized electromagnetic field used
Parameters
Measurand Value Type Method Mass Remarks
SAR 6 µW/g spatial average measured cf. remarks at 1 µW/cm²
power density 100 µW/cm² spatial average measured - -

Exposure 3

Main characteristics
Frequency 51.76 GHz
Type
Polarization
  • circular
Exposure duration continuous for 5 min
Exposure setup
Exposure source
Additional info left-handed circular polarized electromagnetic field used
Parameters
Measurand Value Type Method Mass Remarks
SAR 6 µW/g spatial average measured cf. remarks at 1 µW/cm²
power density 100 µW/cm² spatial average measured - -

Exposure 4

Main characteristics
Frequency 51.68–51.85 GHz
Type
Polarization
  • circular
Exposure duration continuous for 5 min
Exposure setup
Exposure source
Additional info left-handed and right-handed circular polarized electromagnetic field used
Parameters
Measurand Value Type Method Mass Remarks
SAR 6 µW/g spatial average measured cf. remarks at 1 µW/cm²
power density 100 µW/cm² spatial average measured - -

Reference articles

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

At all the frequencies that were studied, right-handed-polarized microwaves effectively influenced the genome conformational state (GCS) of X-radiated cells, whereas left-handed polarization was ineffective.
Conversely, right-handed polarization was ineffective and left-handed polarized electromagnetic irradiation influenced the GCS when intact cells were exposed to microwaves.
It was shown that the effects of left- and right-handed electromagnetic irradiation on the cells become the same at 50 cGy. This dose is too small to damage any cellular structures except DNA. The results suggest that the target of resonant interaction between E. coli cells and millimeter waves appears to be chromosomal DNA.

Study character:

Study funded by

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