Study type: Medical/biological study (experimental study)

Low intensity electromagnetic irradiation with 70.6 and 73 GHz frequencies affects Escherichia coli growth and changes water properties. med./bio.

Published in: Cell Biochem Biophys 2011; 60 (3): 275-281

Aim of study (acc. to editor)

To study the effects of millimeter waves (70.6 and 73 GHz) on Escherichia coli growth and the properties of water.

Background/further details

The millimeter waves of the 70.6 and 73 GHz frequency are resonant for Escherichia coli, but not for water. Escherichia coli was exposed directly (on solid growth medium), in bi-distilled water or in assay buffer. Additional experiments were performed with Escherichia coli, incubated for 10 minutes in bi-distilled water or in assay buffer exposed with millimeter waves for one hour.
Furthermore, bi-distilled water was exposed and investigated.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 70.6 GHz
Modulation type: AM
Exposure duration: continuous for 0.5, 1 and 2 h; the 1 h exposure was additionally repeated after 2 h hour rest period
Exposure 2: 73 GHz
Modulation type: AM

Exposure 1

Main characteristics
Frequency 70.6 GHz
Type
Charakteristic
Exposure duration continuous for 0.5, 1 and 2 h; the 1 h exposure was additionally repeated after 2 h hour rest period
Modulation
Modulation type AM
Modulation frequency 1 Hz
Exposure setup
Exposure source
Distance between exposed object and exposure source 20 cm
Chamber closed chamber
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
power density 0.06 mW/cm² - measured - -

Exposure 2

Main characteristics
Frequency 73 GHz
Type
Charakteristic
Modulation
Modulation type AM
Modulation frequency 1 Hz
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
power density 0.06 mW/cm² - measured - -

Reference articles

  • Tadevosian A et al. (2009): [Effect of coherent extremely high-frequency and low-intensity electromagnetic radiation on the activity of membrane systems in Escherichia coli]
  • Tadevosyan H et al. (2008): Extremely high frequency electromagnetic radiation enforces bacterial effects of inhibitors and antibiotics.
  • Tadevosian A et al. (2007): [The effects of electromagnetic radiation of extremely high frequency and low intensity on the growth rate of bacteria Escherichia coli and the role of medium pH].
  • Trchunian A et al. (2001): [Membranotropic effects of electromagnetic radiation of extremely high frequency in Escherichia coli].

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

The growth rate of Escherichia coli decreased after exposure to 70.6 and 73 GHz millimeter waves (1 and 2 h) in bi-distilled water and in the assay buffer. Two hours after exposure termination, the growth rate recovered.
Exposure of water or buffer alone and subsequent incubation with Escherichia coli had no effect on bacterial growth.
Water properties (optical density, pH, and electric conductance) were also changed after exposure.
The data indicate that millimeter wave exposure to 70.6 and 73 GHz could interact with bacteria and the surrounding medium (water).

Study character:

Study funded by

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