Study type: Medical/biological study (experimental study)

Effects of 2450 MHz electromagnetic fields with a wide range of SARs on methylcholanthrene-induced transformation in C3H10T1/2 cells med./bio.

By: Wang J, Sakurai T, Koyama S, Komatubara Y, Suzuki Y, Taki M, Miyakoshi J
Published in: J Radiat Res 2005; 46 (3): 351-361
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Aim of study (acc. to author)

To study whether 2450 MHz continuous wave high frequency electromagnetic fields could induce cancer-like changes in mouse cells, and whether these electromagnetic fields could initiate malignant or synergistic transformation.

Background/further details

The cells were exposed to high frequency electromagnetic fields alone and/or were treated with a known initiating chemical, methylcholanthrene (2.5 µg/ml). TPA was used as a positive control tumor promotor (5 ng/ml) that could enhance transformation frequency initiated by methylcholanthrene in multistage carcinogenesis.
Temperature controls were also performed (38, 40, 42, and 44°C).

Endpoint

Exposure

Exposure Parameters
Exposure 1: 2.45 GHz
Modulation type: CW
Exposure duration: continuous for 2 h
  • SAR: 200 mW/g maximum (100 W/kg, 50 W/kg, 20 W/kg, 10 W/kg and 5 W/kg)

Exposure 1

Main characteristics
Frequency 2.45 GHz
Charakteristic
  • guided field
Exposure duration continuous for 2 h
Modulation
Modulation type CW
Exposure setup
Exposure source
  • rectangular waveguide in TE10 mode(110 mm wide x 55 mm high x 310 mm deep)
Additional info One end of the waveguide was terminated with a short circulated plate to generate standing waves in the waveguide.
Parameters
Measurand Value Type Method Mass Remarks
SAR 200 mW/g maximum calculated - 100 W/kg, 50 W/kg, 20 W/kg, 10 W/kg and 5 W/kg
Additional parameter details

SAR was calculated using FDTD method. Power sensors monitored the incidence and reflected electromagnetic power.

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 revealed in the malignant transformation frequency between the controls and high frequency electromagnetic fields with or without TPA. However, the transformation frequency for irradiation at a SAR value of more than 100 W/kg with methylcholanthrene or "methylcholanthrene plus TPA" was increased compared with "methylcholanthrene alone" or "methylcholanthrene plus TPA".
On the other hand, the corresponding heat groups ("heat alone", "heat + methylcholanthrene", and "heat + methylcholanthrene + TPA") did not increase transformation compared with each control level in these cells.
The data suggest that 2450 MHz high frequency electromagnetic fields could not contribute to the initiation stage of tumor formation, but it may contribute to the promotion stage at the extremely high SAR (100 W/kg).

Study character:

Study funded by

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