Study type: Medical/biological study (experimental study)

Proto-oncogene mRNA levels and activities of multiple transcription factors in C3H 10T 1/2 murine embryonic fibroblasts exposed to 835.62 and 847.74 MHz cellular phone communication frequency radiation. med./bio.

Published in: Radiat Res 1999; 151 (3): 300-309

Aim of study (acc. to author)

To determine whether two different modulated radiofrequencies of the type generally used in cellular phones (835.62 MHz (FMCW) and 835.62 MHz (CDMA)) could elicit a general stress response in a biological system.

Background/further details

Changes in proto-oncogene expression, determined by measuring Fos, Jun, and Myc mRNA levels as well as by the DNA-binding activity of the AP1, AP2 and NFkB transcription factors, were used as indicators of a general stress response.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 835.62 MHz
Exposure duration: continuous for 24 h or 4 days
Exposure 2: 847.74 MHz
Exposure duration: continuous for 24 h or 4 days

Exposure 1

Main characteristics
Frequency 835.62 MHz
Type
Charakteristic
  • guided field
Exposure duration continuous for 24 h or 4 days
Additional info FMCW
Modulation
Modulation type cf. additional info
Additional info

FMCW

Exposure setup
Exposure source
Chamber A detailed description of the radial transmission line (RTL) and a temperature-controlled facility containing nine RTLs has been given in the reference articles. The RTL is a shielded irradiator consisting of a parallel-plate region (43 mm spacing, total radius of 533 mm) with the bottom aluminium plate acting as a thermal homogenizer for the flasks. A central conical antenna (203 mm in diameter) emitted TEM waves radially outward that were terminated by RF-absorbing material backed by a lamina of perforated aluminium.
Setup A total of 16 T-75 culture flasks each containing 40 ml of medium could be distributed angularly around the antenna. The cell layer in the flasks was subjected to a perpendicular EF and a circumferential MF perpendicular to the EF and the direction of propagation inducing a radial component to the EF.
Sham exposure A sham exposure was conducted.
Additional info Sham exposures were performed in an identical RTL without the RF field. The temperature of the culture medium was maintained at 37.0 ± 0.25°C by feedback controllers for each RTL.
Parameters
Measurand Value Type Method Mass Remarks
SAR 0.6 W/kg mean estimated - ± 0.3 W/kg

Exposure 2

Main characteristics
Frequency 847.74 MHz
Type
Charakteristic
  • guided field
Exposure duration continuous for 24 h or 4 days
Additional info CDMA
Modulation
Modulation type cf. additional info
Additional info

CDMA

Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
SAR 0.6 W/kg mean estimated - ± 0.3 W/kg

Reference articles

  • Moros EG et al. (1999): Compact shielded exposure system for the simultaneous long-term UHF irradiation of forty small mammals. II. Dosimetry.
  • 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)

Exposure of cells to a FMCW or CDMA field did not result in any significant variation in Jun and Myc mRNA levels or the DNA-binding activities of AP1, AP2, and NFkB.
Thus it is concluded that it is unlikely that the radiofrequency field is capable of eliciting a general stress response in cells of this cell line. However, the statistically significant increase in Fos expression suggests that the radiation could affect expression of specific genes.

Study character:

Study funded by

Replication studies

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