Study type: Medical/biological study (experimental study)

Short-term exposure to a 1439-MHz TDMA signal exerts no estrogenic effect in rats med./bio.

By: Yamashita H, Hata K, Yamaguchi H, Tsurita G, Wake K, Watanabe S, Taki M, Ueno S, Nagawa H
Published in: Bioelectromagnetics 2010; 31 (7): 573-575
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Aim of study (acc. to author)

To study the possible effects of short-term exposure to a 1439 MHz TDMA electromagnetic field on estrogenic activity in rats.

Background/further details

64 ovariectomized rats were divided into four groups (each group n=16): 1) electromagnetic field exposure, 2) sham exposure, 3) cage control, and 4) 17β-estradiol injection (as positive control).
Since the rat estrous cycle lasts four days, three consecutive days of exposure were selected followed by sacrifice on day 4.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 1,439 MHz
Modulation type: pulsed
Exposure duration: continuous for 4 hr/day on 3 consecutive days
  • power: 2.25 W
  • SAR: 5.5 W/kg average over mass (brain) (5.5 W/kg - 6.1 W/kg)
  • SAR: 6.1 W/kg average over mass (brain)
  • SAR: 0.88 W/kg average over mass (whole body) (0.88 W/kg - 0.99 W/kg)
  • SAR: 0.99 W/kg average over mass (whole body)

General information

rats were treated in four groups: i) EMF exposure ii) sham exposure iii) cage control iv) 17 beta-estradiol injection (positive control)

Exposure 1

Main characteristics
Frequency 1,439 MHz
Type
Exposure duration continuous for 4 hr/day on 3 consecutive days
Modulation
Modulation type pulsed
Pulse width 20 ms
Duty cycle 33 %
Exposure setup
Exposure source
Setup anechoic chamber with a quarter-wavelength monopole antenna on the metal floor and a turntable for 8 tubes; distance between the rat and the ground = 9 mm; distance between the rat's nose and the antenna = 21 mm
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
power 2.25 W - - - -
SAR 5.5 W/kg average over mass measured and calculated brain 5.5 W/kg - 6.1 W/kg
SAR 6.1 W/kg average over mass measured and calculated brain -
SAR 0.88 W/kg average over mass measured and calculated whole body 0.88 W/kg - 0.99 W/kg
SAR 0.99 W/kg average over mass measured and calculated whole body -

Reference articles

  • Hata K et al. (2005): Short term exposure to 1439 MHz pulsed TDMA field does not alter melatonin synthesis in rats
  • Yamaguchi H et al. (2003): 1439 MHz pulsed TDMA fields affect performance of rats in a T-maze task only when body temperature is elevated
  • Tsurita G et al. (2000): Biological and morphological effects on the brain after exposure of rats to a 1439 MHz TDMA field

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

The short-term exposure to a 1439 MHz electromagnetic field, as used in Japanese mobile phones, altered neither the serum estrogen concentration nor estrogenic activity in female ovariectomized rats.

Study character:

Study funded by

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