Study type: Medical/biological study (experimental study)

Comparison of the genotoxic effects induced by 50 Hz extremely low-frequency electromagnetic fields and 1800 MHz radiofrequency electromagnetic fields in GC-2 cells med./bio.

Published in: Radiat Res 2015; 183 (3): 305-314

Aim of study (acc. to author)

The genotoxic effects of exposure of mouse spermatocyte-derived cells to either a 50 Hz or 1800 MHz electromagnetic field should be investigated and compared.

Background/further details

Cells were either exposed to a 50 Hz magnetic field with 1 mT (group 1), 2 mT (group 2) or 3 mT (group 3) or to a 1800 MHz electromagnetic field with an SAR value of 1 W/kg (group 4), 2 W/kg (group 5) or 4 W/kg (group 6). For each exposure group, a corresponding sham exposure was conducted.
Hydrogen peroxide was used as a positive control in the viability and the comet assay and etoposide was used as a positve control in the detection of gamma-H2AX foci. All experiments were performed at least in triplicates.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: intermittent 5 min field on and 10 min field off for 24 h
Exposure 2: 1,800 MHz
Exposure duration: intermittent 5 min field on and 10 min field off for 24 h
  • SAR: 1 W/kg (group 4)
  • SAR: 2 W/kg (group 5)
  • SAR: 4 W/kg (group 6)

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration intermittent 5 min field on and 10 min field off for 24 h
Exposure setup
Exposure source
Chamber cells were exposed in petri dishes
Setup two mu-metal box chambers (each randomly assigend to exposure or sham exposure) in an incubator; each chamber contained 2 coils with 56 windings, 2 coils with 50 windings, two fans, a petri dish holder and a temperature sensor; 37-37.5°C, 5% CO2 and 95% humidity were maintained; nonuniformity of the magnetic field was <1% at all possible petri dish locations
Sham exposure A sham exposure was conducted.
Additional info temperature difference between the exposure and the sham exposure chambers did not exceed 0.1°C
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1 mT - - - group 1
magnetic flux density 2 mT - - - group 2
magnetic flux density 3 mT - - - group 3

Exposure 2

Main characteristics
Frequency 1,800 MHz
Type
Exposure duration intermittent 5 min field on and 10 min field off for 24 h
Additional info GSM talk mode simulation
Exposure setup
Exposure source
Chamber cells were exposed in petri dishes
Setup two rectangular waveguide chambers (each randomly assigend to exposure or sham exposure); 6 petri dishes were exposed simultaneously in each chamber in the magnetic field maximum with a perpendicularly polarized electric field; 37°C, 5% CO2 and 95% humidity were maintained; maximum temperature rise of 0.03°C/(W/kg)
Sham exposure A sham exposure was conducted.
Additional info temperature difference between the exposure and sham exposure chambers did not exceed 0.1°C
Parameters
Measurand Value Type Method Mass Remarks
SAR 1 W/kg - measured - group 4
SAR 2 W/kg - measured - group 5
SAR 4 W/kg - measured - group 6

Reference articles

  • Liu C et al. (2013): Exposure to 1800 MHz radiofrequency electromagnetic radiation induces oxidative DNA base damage in a mouse spermatocyte-derived cell line
  • Focke F et al. (2010): DNA fragmentation in human fibroblasts under extremely low frequency electromagnetic field exposure
  • Antonini RA et al. (2006): Extremely low-frequency electromagnetic field (ELF-EMF) does not affect the expression of alpha3, alpha5 and alpha7 nicotinic receptor subunit genes in SH-SY5Y neuroblastoma cell line

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

No significant differences were found in cell viability between the exposure groups and their sham exposures, respectively.
In the alkaline comet assay, group 3 (50 Hz, 3 mT) showed a significant increase of DNA damage compared to the sham exposure. Likewise, a significant increase of gamma-H2AX foci was found in group 3 compared to the sham exposure. In the FPG-modified comet assay, significant oxidative nucleic base damage was found in group 6 (1800 MHz, 4 W/kg) in approaches with FPG compared to approaches without FPG. However, this result was not significantly different from the sham exposure.
The authors conclude that exposure of mouse spermatocyte-derived cells to a 50 Hz magnetic field with 3 mT or to a 1800 MHz electromagnetic field could have a genotoxic effect, though the underlying mechanisms of action seem to be different.

Study character:

Study funded by

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