Study type: Medical/biological study (experimental study)

Multigenerational effects of whole body exposure to 2.14 GHz W-CDMA cellular phone signals on brain function in rats. med./bio.

Published in: Bioelectromagnetics 2014; 35 (7): 497-511

Aim of study (acc. to author)

The effects of a chronic multigenerational exposure of rats to a 2.14 GHz electromagnetic field on development, fertility and brain functions should be investigated.

Background/further details

The present study was designed as an extension of a previous study by the authors (Takahashi et al., 2010) with further parameters and an additional generation (F3) .
12 pregnant rats were divided into 3 groups (n=4 each): 1) sham exposure, 2) low-level exposure and 3) high-level exposure. Exposure started on gestational day 7 with generation P1 and on the first postnatal day the litters were culled to 8 young animals (4 males and 4 females) per mother, resulting in 16 young animals of each sex per group (F1). The mothers were then exposed for further 21 days together with the pups (until weaning) and subsequently, the P1 mothers investigated and the F1 rats were further exposed until 6 weeks of age. Then half of the rats were investigated (8 males and 8 females per group) and the rest was used for mating to generate F2, which was done when the rats were 11 weeks old. F2 rats were treated like F1 rats and were partly investigated after 6 weeks of exposure and partly used to generate generation F3, which was finally killed and examined when the rats were 11 weeks old.
The whole experiment was conducted twice.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 2.14 GHz
Exposure duration: continuous for 20 h/day over 3 generations
low level exposure
Exposure 2: 2.14 GHz
Exposure duration: continuous for 20 h/day over 3 generations
high level exposure

Exposure 1

Main characteristics
Frequency 2.14 GHz
Type
Polarization
  • circular
Exposure duration continuous for 20 h/day over 3 generations
Additional info low level exposure
Additional info downlink signals from base stations of the W-CDMA system in Japan with a bandwidth of 5 MHz, a peak to average power ratio of 3 dB, and a number of codes of 512 in the downlink.
Exposure setup
Exposure source
Chamber acrylic cages
Setup exposure chamber was made of metal with dimensions of 90 x 90 x 40 cm; the inside, except for the roof, was paved with a 6 cm thick planar radio frequency absorber with a reflection loss of more than 20 dB at 2.14 GHz; exposure chamber contained 4 acrylic cages, each containing either one pregnant rat, 1 mother and 8 pups or 4 young animals, depending on the stage of the experiment; two 3/2-wavelength antennas were placed beneath the ceiling at a distance of 1.4-1.8 wavelengths from the rats in the chamber; during exposure 22 ± 3°C and 55 ± 15% humidity were maintained
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
SAR 0.034 W/g mean measured and calculated whole body ± 0.012; for fetuses
SAR 0.081 W/g mean measured and calculated whole body ± 0.04; highest value for young animals before weaning
SAR 0.06 W/g mean measured and calculated whole body ± 0.018; for young animals after weaning
SAR 0.05 W/g mean measured and calculated whole body ± 0.007; highest value for mothers
power 0.97 W - measured - ± 5%

Exposure 2

Main characteristics
Frequency 2.14 GHz
Type
Polarization
  • circular
Exposure duration continuous for 20 h/day over 3 generations
Additional info high level exposure
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
SAR 0.102 W/g mean measured and calculated whole body ± 0.035; for fetuses
SAR 0.244 W/g mean measured and calculated whole body ± 0.12; highest value for young animals before weaning
SAR 0.18 W/g mean measured and calculated whole body ± 0.055; for young animals after weaning
SAR 0.149 W/g mean measured and calculated whole body ± 0.022; highest value for mothers
power 2.91 W - measured - ± 5%

Reference articles

  • Imai N et al. (2011): Effects on rat testis of 1.95-GHz W-CDMA for IMT-2000 cellular phones.
  • Takahashi S et al. (2010): Lack of adverse effects of whole-body exposure to a mobile telecommunication electromagnetic field on the rat fetus.
  • Ogawa K et al. (2009): Effects of gestational exposure to 1.95-GHz W-CDMA signals for IMT-2000 cellular phones: Lack of embryotoxicity and teratogenicity in rats.
  • Wang J et al. (2008): Development and Dosimetry Analysis of a 2-GHz Whole-Body Exposure Setup for Unrestrained Pregnant and Newborn Rats.

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

The body weight was significantly higher in group 3 (high level exposure) of generation F3 compared to the sham exposure group. However, the data were not consistent in both experiments, the difference was slight and the biological significance is unknown. Several organ weights were significantly increased in both exposure groups of offspring generations compared to the sham exposure. However, these data were inconsistent over the generations and between the genders in both experiments. All other parameters were either not significantly different between the exposure groups and the sham exposure group or the differences occured only sporadically and inconsistently.
The authors conclude that a chronic multigenerational exposure of rats to a 2.14 GHz electromagnetic field has no effect on the investigated parameters. Thus, the results of the previous study are confirmed.

Study character:

Study funded by

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