Study type: Medical/biological study (experimental study)

Carcinogenicity study of GSM and DCS wireless communication signals in B6C3F1 mice. med./bio.

Published in: Bioelectromagnetics 2007; 28 (3): 173-187

Aim of study (acc. to author)

The purpose of this in vivo study was to evaluate possible carcinogenic effects in mice exposed to 900 MHz (GSM) and 1747 MHz (DCS) radiofrequency irradiation.

Background/further details

A total of 1170 mice were exposed over a period of two years to three different whole body average specific absorption rates (SAR).

Endpoint

Exposure

Exposure Parameters
Exposure 1: 902–1,747 MHz
Modulation type: pulsed
Exposure duration: repeated daily exposure, 2 h/day, 5 days/week, for 2 years
  • SAR: 33.2 mW/g peak value (whole body)
  • SAR: 4 mW/g average over time (whole body) (phase II: 2.8 mW/g and phase III: 1.0 mW/g)
  • SAR: 11.1 mW/g peak value (whole body)
  • SAR: 1.3 mW/g average over time (whole body) (phase II: 0.93 mW/g and phase III: 0.35 mW/g)
  • SAR: 3.7 mW/g peak value (whole body)
  • SAR: 0.4 mW/g average over time (whole body) (phase II: 0.35 mW/g and phase III: 0.11 mW/g)

Exposure 1

Main characteristics
Frequency 902–1,747 MHz
Type
Exposure duration repeated daily exposure, 2 h/day, 5 days/week, for 2 years
Additional info Exposure was performed with a 902 MHz GSM or a 1747 MHz DCS signal. Reference article: Ebert S, Berdinas Torres V, Frohlich J, Kuster N. 2006. SAR uniformity in Ferris wheel setups used in RF exposure of mice at 900 MHz. (In preparation).
Modulation
Modulation type pulsed
Pulse width 0.57 ms
Duty cycle 12.5 %
Additional info

The exposure signal applied consisted of three phases, each lasting 40 min: GSM Basic (non-DTX), GSM Talk consisting of random changes between the non-DTX (2/3) and DTX (1/3) modes, and GSM Environment consisting of a GSM Talk signal further amplitude-modulated by a statistically calculated power control function, based on data presented by Wiart et al. [2001, publication 12955]. Each timeslot was modulated with a standard random code.

Exposure setup
Exposure source
Chamber Two exposure systems, one for each frequency, were located in separate rooms. Each system consisted of a signal generation unit, control and monitoring unit, and four "Ferris wheel" exposure units, one for each dose level (high, medium, low, and sham). The "Ferris wheel" concept developed by Balzano et al. [2000, publication 7306] was adopted and optimized for this study.
Setup Each wheel, enabling exposure of up to 65 animals, consisted of two parallel, circular, stainless steel metal plates, 117 mm apart, with a conical (GSM) or bi-conical (DCS) antenna in their center, and stainless steel poles forming a short-cut of the cylindrical cavity at a radius of 755 mm. The animals, restrained in tubes similar to those used and approved for inhalation studies, were positioned at a radius (center of wheel to center of tubes) of 700 mm for GSM and 670 mm for DCS. In order to maintain a symmetrical load, missing animals were replaced by conical plastic tubes filled with 36 ml of liquid simulating the dielectrical parameters of muscle tissue. Higher modes were reduced by dielectric bricks between the animals at 902 MHz. Details of the setup and dosimetry are provided in Ebert et al. [2006] (in preparation).
Sham exposure A sham exposure was conducted.
Additional info Male or female mice were each randomized by weight into 9 treatment groups: 2 x 4 RF dose groups (incl. sham) and one untreated cage control group. Loading and unloading of the exposure wheel was done first in/first out resulting in an additional restraint time of up to 32 min for each mouse. The study was performed blind to all scientists involved.
Parameters
Measurand Value Type Method Mass Remarks
SAR 33.2 mW/g peak value measured and calculated whole body -
SAR 4 mW/g average over time measured and calculated whole body phase II: 2.8 mW/g and phase III: 1.0 mW/g
SAR 11.1 mW/g peak value measured and calculated whole body -
SAR 1.3 mW/g average over time measured and calculated whole body phase II: 0.93 mW/g and phase III: 0.35 mW/g
SAR 3.7 mW/g peak value measured and calculated whole body -
SAR 0.4 mW/g average over time measured and calculated whole body phase II: 0.35 mW/g and phase III: 0.11 mW/g

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)

There was no significant increase in the organ-related tumor incidence of any particular tumor type in the radio frequency exposed groups.

Study character:

Study funded by

Comments on this article

Related articles