Study type: Medical/biological study (experimental study)

Adaptive response in human blood lymphocytes exposed to non-ionizing radiofrequency fields: resistance to ionizing radiation-induced damage med./bio.

Published in: J Radiat Res 2014; 55 (2): 210-217

Aim of study (acc. to author)

To examine whether an exposure of human blood lymphocytes to radiofrequency fields exhibits an adaptive response by resisting genotoxic effects from subsequent exposure to X-radiation.

Background/further details

Adaptive response: Former studies have shown that different cell types exposed to an extremely small adaptation dose of a genotoxic agent are less susceptible to the induction of a genetic damage when given a higher challenge dose of the same or a similar genotoxic agent.
Blood lymphocytes of four male healthy donors were stimulated for 24 h with phytohaemagglutinin and then exposed for 20 hours to an adaptive dose of 1950 MHz radiofrequency field to a specific absorption rate of 0.3 W/kg or sham exposed. This was followed by a challenge dose of x-radiation (1.0 or 1.5 Gy). Cells were collected after 72 h total culture period and the frequency of micronuclei was recorded.
Further experiments were performed with X-radiation and mitomycin C as an adaptive dose. The results are not presented here.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 1,950 MHz
Exposure duration: continuous for 20 hours

Exposure 1

Main characteristics
Frequency 1,950 MHz
Type
Exposure duration continuous for 20 hours
Exposure setup
Exposure source
Chamber two exposure chambers of rectangular waveguides (WR 430) housed (together with sham waveguide) in commercial incubator; waveguides fed by amplified signal of a signal generator
Setup samples placed on four-layer plexiglass stand with 35 mm Petri dishes on each layer; the Petri dishes containing the diluted blood from each donor were kept in the outer positions and exposed to 0.3 W/kg, while dummy samples were placed in the inner positions of the incubator (37.0 ± 0.5°C, 95% air, 5% carbon dioxide)
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
SAR 0.3 W/kg mean calculated - -

Reference articles

  • Zeni O et al. (2012): Radiofrequency radiation at 1950 MHz (UMTS) does not affect key cellular endpoints in neuron-like PC12 cells
  • Zeni O et al. (2012): Induction of an adaptive response in human blood lymphocytes exposed to radiofrequency fields: Influence of the universal mobile telecommunication system (UMTS) signal and the specific absorption rate

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

Cell cultures exposed to a radiofrequency field as an adaptive dose before treated with a challenge dose of 1.5 Gy x-radiation (but not 1.0 Gy) showed a significant decrease in the number of micronuclei compared to those treated with x-radiation alone. However, a large variability was observed between the donors. The proliferation index was similar between cell cultures pre-exposed to an adaptive dose of radiofrequency fields and subsequently treated with X-radiation and those cell cultures treated with X-radiation alone.
The authors conclude that exposure of human lymphocytes to radiofrequency fields exhibits an adaptive response by resisting genotoxic effects from subsequent exposure to X-radiation.

Study character:

Study funded by

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