Study type: Medical/biological study (experimental study)

Long-term exposure of E-mu-Pim1 transgenic mice to 898.4 MHz microwaves does not increase lymphoma incidence. med./bio.

Published in: Radiat Res 2002; 158 (3): 357-364

Aim of study (acc. to author)

To test whether exposure to 0.25, 1.0, 2.0 and 4.0 W/kg of global system for mobile communication (GSM)-modulated radiofrequency fields increased tumor incidence in Eµ-Pim1 transgenic heterozygous mice.

Background/further details

A total of 120 heterozygous and 120 wild-type mice were exposed at each of the exposure levels. 120 mice of each strain were sham-exposed and there were 120 freely moving negative control animals of each strain. 30 heterozygotes and 30 wild-type mice were used as positive controls. 100 sentinel mice were used for health monitoring purposes.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 898.4 MHz
Modulation type: pulsed
Exposure duration: repeated daily exposure for 1 h/day, 5 days/week for up to 104 weeks
  • SAR: 0.25 W/kg unspecified (unspecified)
  • SAR: 1 W/kg unspecified (unspecified)
  • SAR: 2 W/kg unspecified (unspecified)
  • SAR: 4 W/kg unspecified (unspecified)

Exposure 1

Main characteristics
Frequency 898.4 MHz
Type
Charakteristic
Exposure duration repeated daily exposure for 1 h/day, 5 days/week for up to 104 weeks
Modulation
Modulation type pulsed
Pulse width 0.6 ms
Repetition frequency 217 Hz
Exposure setup
Exposure source
Distance between exposed object and exposure source 44 cm
Chamber The exposure systems were radial electromagnetic cavities (''Ferris wheels'') and have been described in the reference article. The mice were exposed or sham-exposed in a total of 15 exposure systems (three at each exposure level including shams) in five exposure rooms.
Setup Each of the 15 exposure systems consisted of a cylindrical parallel plate arrangement with mice restrained individually in 40 clear Perspex tubes arranged radially at a distance of 44 cm around a dipole antenna. Mice were loaded into the exposure systems using a two-level randomization supplied by the statistician. Mice sent for necropsy were replaced by phantoms that were both tissue-equivalent and had the average weight of the remaining mice in the cage to maintain constant dosimetry.
Additional info The study was double-blinded. A total of 120 heterozygous and 120 wild-type mice were exposed at each exposure level; 120 mice of each strain were sham-exposed; and there were 120 freely moving negative control mice of each strain that were only transported to the exposure rooms and immediately back to their home rooms. Thirty heterozygotes and 30 wild-type mice were used as positive controls. They were injected with ethylnitrosourea (pH 5.0) at 50 mg/kg body weight and sham-exposed. One hundred sentinel mice were also used for health monitoring purposes so that a total of 1600 mice entered the study.
Parameters
Measurand Value Type Method Mass Remarks
SAR 0.25 W/kg unspecified unspecified unspecified -
SAR 1 W/kg unspecified unspecified unspecified -
SAR 2 W/kg unspecified unspecified unspecified -
SAR 4 W/kg unspecified unspecified unspecified -

Reference articles

  • Balzano Q et al. (2000): An efficient RF exposure system with precise whole-body average SAR determination for in vivo animal studies at 900 MHz.

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 showed no significant difference in the incidence of lymphomas between exposed and sham-exposed groups at any of the exposure levels. No dose-response effect was found.

Study character:

Study funded by

Replicated studies

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