Study type: Medical/biological study (experimental study)

Effects of mobile phone radiation on X-ray-induced tumorigenesis in mice. med./bio.

Published in: Radiat Res 2001; 156 (6): 775-785

Aim of study (acc. to author)

To evaluate the effect of low-level radiofrequency radiation on the development of cancer initiated in mice by ionizing radiation.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 902.5 MHz
Modulation type: FM, CW
Exposure duration: repeated daily exposure, 1.5 h/day, 5 days a week for 78 weeks
  • power: 6.1 W average over time (± 0.8 W)
  • SAR: 1.5 W/kg average over time (whole body) (± 15%)
Exposure 2: 902.4 MHz
Modulation type: pulsed
Exposure duration: repeated daily exposure, 1.5 h/day, 5 days a week for 78 weeks
  • power: 1.3 W average over time (± 0.1 W)
  • SAR: 0.35 W/kg average over time (whole body) (± 15%)

Exposure 1

Main characteristics
Frequency 902.5 MHz
Type
Charakteristic
  • guided field
Exposure duration repeated daily exposure, 1.5 h/day, 5 days a week for 78 weeks
Modulation
Modulation type FM, CW
Additional info

modulated with a random sequence of bytes

Exposure setup
Exposure source
Chamber Three identical rectangular waveguide chambers made of aluminium were used in the study. The exposure chamber consisted of a straight rectangular section (24.8 cm x 20 cm) and of two waveguide-to-coaxial adapters. The total length of the chamber with the adapters was 190 cm. The mice were kept in small cylindrical acrylic restrainers (i.d. 32 mm, length adjustable) preventing them from aligning their longitudinal axis parallel to the electric field. The restrainers were placed 25 at a time on a Styrofoam holder so that each mouse was in the center of the cross section of the waveguide with its longitudinal axis perpendicular to the electric field and the direction of propagation. The distance between adjacent mice was 5 cm. The mice that were missing were replaced with mouse phantoms made of plastic cylinders partly filled with a solution simulating the dielectric properties of muscle at 900 MHz.
Setup Modified and computer-controlled mobile phones were used as signal sources. The signals were amplified by boosters manufactured for vehicle use. RF power meters were used for measuring the input, reflected and output power of the exposure chamber. The output power was absorbed by a coaxial 10 W termination. The SAR was controlled daily by adjusting the input power.
Additional info The animals were randomized into four equal groups: NMT exposure, GSM exposure, sham exposure and cage control. The sham exposed group was kept in an unenergised waveguide chamber. The mice in all groups except the cage-control group were exposed to ionizing radiation at the beginning of the study. The total-body dose was 4 Gy delivered as three equal fractions of 1.33 Gy at 1-week intervals with linear accelerators. The dose rate was 0.51 Gy/min. To ensure a uniform irradiation of the whole body, a Plexiglas scatterer was placed 15 cm above the animals.
Parameters
Measurand Value Type Method Mass Remarks
power 6.1 W average over time measured - ± 0.8 W
SAR 1.5 W/kg average over time measured and calculated whole body ± 15%

Exposure 2

Main characteristics
Frequency 902.4 MHz
Type
Charakteristic
  • guided field
Exposure duration repeated daily exposure, 1.5 h/day, 5 days a week for 78 weeks
Modulation
Modulation type pulsed
Duty cycle 12.5 %
Repetition frequency 217 Hz
Additional info

modulated with a random sequence of bytes

Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
power 1.3 W average over time measured - ± 0.1 W
SAR 0.35 W/kg average over time measured and calculated whole body ± 15%

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

The results did not reveal any obvious effects of low-level radiofrequency radiation on X-ray-induced tumorigenesis.

Study character:

Study funded by

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