Study type: Medical/biological study (experimental study)

Evidence for microwave carcinogenesis in vitro med./bio.

By: Balcer-Kubiczek EK, Harrison GH
Published in: Carcinogenesis 1985; 6 (6): 859-864
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Aim of study (acc. to author)

To investigate the carcinogenic activity of 2.45 GHz microwave radiation combined with benzpyrene or X-rays, using an in vitro assay for malignant transformation in C3H 10T1/2 mouse embryo fibroblasts.
Additional experiments were performed to assess the effect of a non-cytotoxic and non-transforming concentration of the tumor promotor TPA on transformation induction in cells treated with microwave radiation and X-rays.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 2.45 GHz
Modulation type: pulsed
Exposure duration: 24 h

Exposure 1

Main characteristics
Frequency 2.45 GHz
Type
Waveform
Exposure duration 24 h
Additional info Horizontal polarization
Modulation
Modulation type pulsed
Pulse width 83 µs
Packets per second 1
Repetition frequency 120 Hz
Exposure setup
Exposure source
Chamber Anechoic chamber (2.6 m x 2.6 m x 2.6 m)
Setup Culture flasks immeresed into water-bath (60 x 60 x 12 cm) which was kept in anechoic chamber.
Parameters
Measurand Value Type Method Mass Remarks
power 1 kW - cf. remarks - forward power to the antenna
SAR 4.4 mW/g mean measured cf. remarks +/- 8 W/kg at cell monolayer, 2.5 cm below the water level
Additional parameter details

Incident power densities were uniform to within 10% in 25 cm x 25 cm region where the flasks were located. Cells were pre-irradiated with MW for 6 h, exposed to 100 kVp X-ray to 1.5 to 6 GY at a dose rate of 0.39 Gy/min.

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

Microwave exposure reduced the plating efficiency of 50%, while TPA increased it by 40%. Microwave radiation had no effect on transformation induced by benzpyrene or X-rays in the absence of tumor promoter. TPA treatment of cells previously irradiated with microwaves and X-rays yielded a statistically significant increase (3.5- or 1.6-fold) in transformation when compared with the transformation frequency of cells previously irradiated with X-rays alone at 1.5 and 4.5 Gy, respectively. The results suggest that low-level 2.45 GHz microwave radiation can induce latent transformation damage which can then be revealed by the action of tumor promoters.

Study character:

Study funded by

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