Study type: Medical/biological study (experimental study)

Measurement of DNA damage in mammalian cells exposed in vitro to radiofrequency fields at SARs of 3-5 W/kg med./bio.

By: Li L, Bisht KS, Lagroye I, Zhang P, Straube WL, Moros EG, Roti Roti JL
Published in: Radiat Res 2001; 156 (3): 328-332
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Aim of study (acc. to author)

To determine whether exposure of mammalian cells to radiofrequency fields (847.74 MHz CDMA and 835.62 FDMA) could induce DNA damage in murine fibroblasts.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 847.74 MHz
Exposure duration: continuous for 2 or 4 h
Exposure 2: 835.62 MHz
Exposure duration: continuous for 2 or 4 h
Exposure 3: 847.74 MHz
Exposure duration: continuous for 24 h
  • SAR: 4.9 W/kg
Exposure 4: 835.62 MHz
Exposure duration: continuous for 24 h
  • SAR: 5.1 W/kg

General information

CDMA, FDMA and sham exposures were performed simultaneously at 37.0 ± 0.3°C.

Exposure 1

Main characteristics
Frequency 847.74 MHz
Type
Charakteristic
  • guided field
Exposure duration continuous for 2 or 4 h
Modulation
Modulation type cf. additional info
Additional info

CDMA
Exposure setup
Exposure source
Chamber The Radial Transmission Line (RTL) irradiator and the shielded and temperature-controlled facility housing nine RTLs have been described and comprehensively characterised previously [Moros et al., 1999].
Setup Each RTL was formed by two parallel square (4 ft. x 4 ft.) aluminium plates with a central antenna surrounded by 16 tightly capped T-75 flasks.
Sham exposure A sham exposure was conducted.
Additional info The rather high SAR values were obtained by placing a 3-mm shim of alumina under each flask thus increasing the thickness of the dielectric material between the lower plate and the cell layer.
Parameters
Measurand Value Type Method Mass Remarks
SAR 3.2 W/kg minimum measured and calculated - -
SAR 3.8 W/kg mean measured and calculated - -
Additional parameter details

Each experiment included a sample that was irradiated with 2 Gy of γ rays at dose rates of 6.55 cGy/min to 0.18 Gy/min.

Measurement and calculation details

SAR values were calculated and measured as described by Moros et al. [1999].

Exposure 2

Main characteristics
Frequency 835.62 MHz
Type
Charakteristic
  • guided field
Exposure duration continuous for 2 or 4 h
Modulation
Modulation type cf. additional info
Additional info

FDMA
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
SAR 3.2 W/kg minimum measured and calculated - -
SAR 3.8 W/kg mean measured and calculated - -

Exposure 3

Main characteristics
Frequency 847.74 MHz
Type
Charakteristic
  • guided field
Exposure duration continuous for 24 h
Modulation
Modulation type cf. additional info
Additional info

CDMA
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
SAR 4.9 W/kg - measured and calculated - -

Exposure 4

Main characteristics
Frequency 835.62 MHz
Type
Charakteristic
  • guided field
Exposure duration continuous for 24 h
Modulation
Modulation type cf. additional info
Additional info

FDMA
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
SAR 5.1 W/kg - measured and calculated - -

Reference articles

  • Vijayalaxmi et al. (2001): Cytogenetic studies in human blood lymphocytes exposed in vitro to radiofrequency radiation at a cellular telephone frequency (835.62 MHz, FDMA)
  • Moros EG et al. (1999): The radial transmission line as a broad-band shielded exposure system for microwave irradiation of large numbers of culture flasks

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

No statistically significant differences in either comet moment or comet length between sham-exposed cells and those exposed for 2, 4 or 24 h to CDMA or FDMA radiations in either exponentially growing or plateau-phase cells were found. The results show that exposure of cultured C3H 10T1/2 cells at 37°C (CDMA or FDMA) at SAR values of up to 5.1 W/kg did not induce measurable DNA damage.

Study character:

Study funded by

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