Study type: Medical/biological study (experimental study)

Proliferation, Oxidative Stress and Cell Death in Cells Exposed to 872 MHz Radiofrequency Radiation and Oxidants. med./bio.

Published in: Radiat Res 2008; 170 (2): 235-243

Aim of study (acc. to author)

To investigate the effects of pulsed wave, GSM modulated or continuous wave 872 MHz radiofrequency irradiation on cell proliferation, apoptosis, other forms of cell death, and oxidative stress.

Background/further details

To examine possible combined effects of radiofrequency exposure with other agents, cells were treated with menadione to induce reactive oxygen species, and with tertiary butylhydro-peroxide to induce lipid peroxidation. The experiments were performed isothermal and with a specific absorption rate of 5 W/kg which is obviously above the ICNIRP limit value.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 872 MHz
Modulation type: CW
Exposure duration: continuous for 1 or 24 h
Exposure 2: 872 MHz
Modulation type: pulsed
Exposure duration: continuous for 1 or 24 h

General information

A comprehensive description of the exposure system including details about the dosimetry has been published in [Hoyto et al., 2006].

Exposure 1

Main characteristics
Frequency 872 MHz
Type
Charakteristic
  • guided field
Exposure duration continuous for 1 or 24 h
Modulation
Modulation type CW
Exposure setup
Exposure source
Chamber CO2 (5%) and temperature-controlled air were provided to the aluminium RF resonator by ventilation from a cell culture incubator. Temperature increases in the cell cultures were eliminated by placing the culture dishes on a heat exchanger with water circulation, which ensured isothermal conditions (37.0 ± 0.3°C).
Setup Cells in two 55-mm glass or plastic Petri dishes were RF exposed in one chamber, and two dishes were simultaneously sham-exposed in an identical chamber.
Sham exposure A sham exposure was conducted.
Additional info The cells were subjected to four conditions: no exposure, RF radiation, chemical treatment, and RF radiation plus chemical treatment.
Parameters
Measurand Value Type Method Mass Remarks
SAR 5 W/kg - - - -

Exposure 2

Main characteristics
Frequency 872 MHz
Type
Charakteristic
  • guided field
Exposure duration continuous for 1 or 24 h
Modulation
Modulation type pulsed
Repetition frequency 217 Hz
Additional info

GSM-like

Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
SAR 5 W/kg - - - -

Reference articles

  • Höytö A et al. (2006): Modest increase in temperature affects ODC activity in L929 cells: Low-level radiofrequency radiation does not.

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Investigated organ system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

The lipid peroxidation induced by tertiary butylhydro-peroxide was statistically significant increased in radio frequency exposed human neuroblastoma cells, but not in radio frequency exposed mouse fibroblasts. Additionally, menadione-induced caspase 3 activity was statistically significant increased in radio frequency exposed mouse fibroblasts, but not in radio frequency exposed human neuroblastoma cells. Both differences were statistically significant only for the GSM-modulated signal. The other endpoints were not significantly affected in any of the experimental conditions, and no effects were observed from exposure to radio frequency irradiation alone.
The authors conclude that the positive findings may be due to chance, but they may also reflect effects that occur only in cells sensitized by chemical stress. Further studies are required to investigate the reproducibility and dose response of the possible effects.

Study character:

Study funded by

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