Study type: Medical/biological study (experimental study)

DNA damage and micronucleus induction in human leukocytes after acute in vitro exposure to a 1.9 GHz continuous-wave radiofrequency field med./bio.

By: McNamee JP, Bellier PV, Gajda GB, Miller SM, Lemay EP, Lavallee BF, Marro L, Thansandote A
Published in: Radiat Res 2002; 158 (4): 523-533
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Aim of study (acc. to author)

To investigate whether acute (2h) exposure to a 1.9 GHz continuous wave (CW) radiofrequency field could elicit primary DNA damage and/or induce micronucleus formation in cultured human leukocytes.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 1.9 GHz
Modulation type: CW
Exposure duration: continuous for 2 h

Exposure 1

Main characteristics
Frequency 1.9 GHz
Type
Charakteristic
  • guided field
Polarization
  • circular
Exposure duration continuous for 2 h
Modulation
Modulation type CW
Exposure setup
Exposure source
Chamber The waveguide applicators consisted of an aluminium tube, 110 mm in diameter and 210 mm long, which was shorted at one end and open at the other. They were fed from two identical excitation probes (monopoles, 33 mm long x 4 mm in diameter) spaced 90° apart and located 50 mm from the shorted end. All six waveguide applicators were housed in a wooden enclosure lined with MW absorbent foam. They were spaced 250 mm apart (center to center) and were separated by a shield consisting of a 200 mm x 300 mm aluminium sheet sandwiched between 6.4-mm thick absorber panels and extending 100 mm higher than the top of the sample dishes.
Setup The sample holder located on the top of the open aperture of the waveguide consisted of two unequal-sized Petri dishes. The inner dish of 60 mm diameter containing the blood cell culture sat concentrically within the outer dish of 150 mm diameter on 3.2-mm plastic standoffs and was circulated by temperature-controlled coolant water maintaining the temperature in the culture at 37 ± 0.5°C. The coolant (130 ml) was kept at the same level as the sample (10 ml) for optimal SAR uniformity.
Sham exposure A sham exposure was conducted.
Additional info A total of five separate experiments were conducted over 3 months, each consisting of five RF-field exposed cultures and concurrent sham exposed, negative (incubator) and positive (1.5 Gy 137Cs γ radiation; at 0.987 Gy/min) controls.
Parameters
Measurand Value Type Method Mass Remarks
SAR 0.1 W/kg mean measured and calculated - -
SAR 0.26 W/kg mean measured and calculated - -
SAR 0.92 W/kg mean measured and calculated - -
SAR 2.4 W/kg mean measured and calculated - -
SAR 10 W/kg mean measured and calculated - -
Additional parameter details

The SAR for 95% of the sample volume was found to be ±24% of the mean SAR.

Measurement and calculation details

The input powers were monitored using a directional coupler and a power meter. Thermometric measurements using a thermistor probe were performed to establish absolute SAR values at various points in the sample, whereas relative E-field measurements were made using an isotropic E-field probe to asses the SAR distribution in the aperture plane.

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 results provide no evidence to support the hypothesis that acute, nonthermal, RF-field exposure causes appreciable DNA damage in human leukocytes.

Study character:

Study funded by

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