Study type: Medical/biological study (experimental study)

Non-thermal effects of 2.45GHz microwaves on spindle assembly, mitotic cells and viability of Chinese hamster V-79 cells. med./bio.

Published in: Mutation Research - Fundamental and Molecular Mechanism of Mutagenesis 2011; 716: 1-9

Aim of study (acc. to author)

To analyse mitotic spindle apparatus alteration, mitotic index and apoptosis in V79 cells after 2.45 GHz microwave exposure.

Background/further details

The following groups were examined: 1.) exposure at 2.45 GHz to a power density of 5 mW/cm2, 2.) exposure at 2.45 GHz to a power density of 10 mW/cm2, 3.) sham exposure and 4.) incubation in a thermostatic bath mimicking the same temperature increase recorded during exposure (37°C, 38°C, 39°C, 40°C and 41°C).
Mitotic spindle apparatus alterations and the mitotic index were directly examined after the exposure period, while apoptosis was regarded 24 h after exposure. All the experiments were performed in triplicate.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 2.45 GHz
Modulation type: CW
Exposure duration: continuous for 15 min
Exposure 2: 2.45 GHz
Modulation type: CW
Exposure duration: continuous for 15 min

Exposure 1

Main characteristics
Frequency 2.45 GHz
Type
Exposure duration continuous for 15 min
Modulation
Modulation type CW
Exposure setup
Exposure source
Setup cells placed on 26 mm x 76 mm stove-sterilized glass microscope slides placed in 90 mm Petri dishes, Petri dishes placed inside the GTEM cell
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 4.36 V/m minimum calculated - on the glass slide
electric field strength 14.4 V/m maximum calculated - on the glass slide
SAR 0.04 W/kg minimum calculated - -
SAR 0.51 W/kg maximum calculated - -
power density 5 mW/cm² - calculated - -

Exposure 2

Main characteristics
Frequency 2.45 GHz
Type
Exposure duration continuous for 15 min
Modulation
Modulation type CW
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 6.18 V/m minimum calculated - on the glass slide
electric field strength 20.34 V/m maximum calculated - on the glass slide
SAR 0.09 W/kg minimum calculated - -
SAR 1.03 W/kg maximum calculated - -
power density 10 mW/cm² - calculated - -

Reference articles

  • Kuster N et al. (2000): Recommended minimal requirements and development guidelines for exposure setups of bio-experiments addressing the health risk concern of wireless communications.

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

In comparison to the control group, a significant increase in the number of cells with aberant mitotic spindle apparatus was detected in the exposure groups (5 and 10 mW/cm2, frequency of aberant mitotic spindle apparatus increased significantly with increasing power density), but not in the temperature control groups. The number of apoptotic cells was significantly increased in both exposure groups (frequency of apoptotic cells increased significantly with increasing power density), while the mitotic index decreased, as compared to the sham exposed groups and the temperature controls. The temperature effect on the correct assembly of mitotic spindle apparatus was negliable up to 41°C. Apoptosis was induced only when the medium temperature achieved 40°C, thus exceeding the maximum value registered during exposure (ca. 38°C at 5 W/cm2 and ca. 39°C at 10 W/cm2).
The authors hypothesize that short term microwave exposures at 2.45 GHz cause alterations of the mitotic spindle apparatus in V79 cells and this represents, in turn, a pro-apoptotic signal.

Study character:

Study funded by

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