Study type: Medical/biological study (experimental study)

Effect of chronic exposure to a GSM-like signal (mobile phone) on survival of female Sprague-Dawley rats: Modulatory effects by month of birth and possibly stage of the solar cycle. med./bio.

Published in: Neuro Endocrinol Lett 2010; 31 (4): 457-473

Aim of study (acc. to author)

To study the effect of chronic exposure to a low intensity GSM-like signal on health and survival of unrestrained female rats kept under identical conditions.

Background/further details

During 1997-2008 two long-term (experiments I and II) and two life-long (experiments III and IV) experiments were performed. In the first two experiments (1997-2000) 12 exposed and 12 sham exposed rats (each experiment) were observed until all surviving rats were sacrificed at 25 (770 days; experiment I) or 19 months of age (580 days; experiment II). In the course of two survival experiments (experiments III and IV: 2002-2005 and 2005-2008) 30 exposed and 30 sham exposed animals (each experiment) were followed up until their natural end or when they became moribund and had to be euthanized (maximal survival time was 36-37 months).

Endpoint

Exposure

Exposure Parameters
Exposure 1: 900 MHz
Modulation type: pulsed
Exposure duration: continuous (except times for feeding, cleaning, health inspection, etc.): 24 months (exp. I), 17 (exp. II), 36 (exp. III), and 37 (exp. IV) months

Exposure 1

Main characteristics
Frequency 900 MHz
Type
Charakteristic
Polarization
  • circular
Exposure duration continuous (except times for feeding, cleaning, health inspection, etc.): 24 months (exp. I), 17 (exp. II), 36 (exp. III), and 37 (exp. IV) months
Modulation
Modulation type pulsed
Pulse width 577 µs
Repetition frequency 217 Hz
Exposure setup
Exposure source
Chamber exposure chambers were placed in two adjacent rooms (no windows) of equal dimensions (RF exposure and sham exposure); no mobile communication possible within the rooms; 12 hours light (28-35 lux) per 24 hours; detailed description of an identical exposure set-up (identical parameters and intensity) in Bartsch H. et al. (2002)
Setup 12 unrestrained animals per cage, located within exposure chamber or sham chamber
Sham exposure A sham exposure was conducted.
Additional info exposure began with 52 (I), 53 (II) , 70 (III) or 63 (IV) days of age depending on experiment group; animals sacrificed at 25 (I) and 19 (II) months of age; groups III and IV observed until natural end
Parameters
Measurand Value Type Method Mass Remarks
power density 100 µW/cm² mean - - cage bottom
SAR 80 mW/kg mean calculated whole body animals 2 months old
SAR 44 mW/kg mean calculated whole body animals 4-6 months old
SAR 38 mW/kg mean calculated whole body animals 11-12 months old

Reference articles

  • Bartsch H et al. (2002): Chronic exposure to a GSM-like signal (mobile phone) does not stimulate the development of DMBA-induced mammary tumors in rats: results of three consecutive studies.

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)

In experiment I no adverse health effects of chronic exposure were detectable, neither by macroscopic nor microscopic pathological examinations. Also in experiment II no apparent macroscopic pathological changes due to irradiation were found.
Median survival was significantly shortened under exposure in experiments III and IV by 9.06%, i.e by 72 days in experiment III and 77 days in experiment IV as compared to the sham exposed rats. Both groups of animals of experiment III showed reduced median survival times by 6.25% compared to the corresponding groups of experiment IV which may be due to the fact that animals of experiment III were born in October and animals of experiment IV in May indicating that the month of birth affects life span.
From the data of the last two experiments it has to be concluded that chronic exposure to a low intensity GSM-like signal may exert negative health effects and shorten survival if treatment is applied sufficiently long and the observational period covers the full life span of the animals concerned. The data show that survival of rats kept under controlled laboratory conditions varies within certain limits depending on the month of birth. To further prove these complex interactions and processes it is necessary to systematically continue the experiments.

Study character:

Study funded by

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