Study type: Medical/biological study (experimental study)

Formation of reactive oxygen species in L929 cells after exposure to 900 MHz RF radiation with and without co-exposure to 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone. med./bio.

Published in: Radiat Res 2007; 167 (3): 306-311

Aim of study (acc. to author)

To study the induction of reactive oxygen species in murine cells exposed to radiofrequency irradiation at 900 MHz, with or without co-exposure to the drinking water mutagen and carcinogen 3-chloro-4-dichloromethyl-5-hydroxy-2-5H-furanone (MX).

Background/further details

3-chloro-4-dichloromethyl-5-hydroxy-2-5H-furanone (MX) is a potent bacterial mutagen produced during chlorination of drinking water.
MX treatment was performed at a subtoxic level of 500 µM, and the radiofrequency field exposure was carried out during the first 10 or 30 min of MX treatment. The formation of reactive oxygen species was investigated at different times until one hour after radiofrequency exposure/co-exposure.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 900 MHz
Modulation type: CW
Exposure duration: continuous for 10 or 30 min
Exposure 2: 900 MHz
Modulation type: pulsed
Exposure duration: continuous for 10 or 30 min

General information

Six conditions were tested for each RF signal: sham exposure and two levels of RF radiation, each alone and together with MX treatment.

Exposure 1

Main characteristics
Frequency 900 MHz
Type
Charakteristic
  • guided field
Exposure duration continuous for 10 or 30 min
Modulation
Modulation type CW
Exposure setup
Exposure source
Chamber The exposure chamber was made of a rectangular waveguide (124 x 248 x 500 mm) and two coax-to-waveguide adapters and was terminated on a matched load.
Setup Two T-75 cell culture flasks containing 15 ml of medium were inserted into the waveguide. The narrow side of the waveguide and the E field were horizontal, i.e., parallel to the liquid layer (2 mm thick) in the rectangular plastic flask.
Sham exposure A sham exposure was conducted.
Additional info The temperature of the waveguide was maintained at 37.0 ± 0.1°C by thermostatted water circulating in a 30-m-long plastic tube (8 mm inner diameter) wound around the waveguide and kept in contact by wooden boards. A polyurethane foam cover was used for thermal insulation.
Parameters
Measurand Value Type Method Mass Remarks
SAR 0.3 W/kg mean measured and calculated - -
SAR 1 W/kg mean measured and calculated - -

Exposure 2

Main characteristics
Frequency 900 MHz
Type
Charakteristic
  • guided field
Exposure duration continuous for 10 or 30 min
Modulation
Modulation type pulsed
Additional info

GSM-modulated signal

Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
SAR 0.3 W/kg mean measured and calculated - -
SAR 1 W/kg mean measured and 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.
  • Allis JW et al. (1977): Measurement of microwave radiation absorbed by biological systems, 1. Analysis of heating and cooling data.

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated material:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

MX treatment alone resulted in a statistically significant increase in the formation of reactive oxygen species for all the treatment durations investigated, confirming that MX is an inductor of oxidative stress in these cells.
But the data provided no evidence that 900 MHz radiofrequency exposure, either alone or in combination with MX, induced formation of reactive oxygen species under any of the experimental conditions investigated.

Study character:

Study funded by

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