Study type: Medical/biological study (experimental study)

Evaluation of oxidant stress and antioxidant defense in discrete brain regions of rats exposed to 900 MHz radiation. med./bio.

Published in: Bratisl Lek Listy 2014; 115 (5): 260-266

Aim of study (acc. to author)

The effects of a whole body exposure of adolescent rats to a 900 MHz electromagnetic GSM field on oxidative stress and the antioxidative system in discrete brain sections should be investigated.

Background/further details

36 rats were equally separated into the three following groups (n=12 in each group): 1) cage control, 2) sham exposure and 3) exposure. Subsequent to exposure (day 29), behavioral analysis was conducted (not part of the present paper, published here: Narayanan et al. 2013) and afterwards, six animals of each group were sacrificed and examined.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 890–915 MHz
Modulation type: pulsed
Exposure duration: intermittent for 1 h/day for 28 days
  • SAR: 1.58 W/kg (according to manufacturer)
  • power density: 146.6 µW/cm² peak value (3 cm away from the phone during incoming call)
  • power density: 2.109 nW/cm² peak value (3 cm away from the phone in "ON" mode during pause intervals)

Exposure 1

Main characteristics
Frequency 890–915 MHz
Type
Exposure duration intermittent for 1 h/day for 28 days
Modulation
Modulation type pulsed
Repetition frequency 217 Hz
Exposure setup
Exposure source
Chamber polypropylene cages (3 animals per cage) measuring 41 cm Œ 28 cm Œ 14 cm, temperature 23°C ± 2°C
Setup phone in silence mode was placed in a wood bottom bamboo wire mesh cage (12 cm Π7 cm Π7 cm) in the center of the home cage with 3 rats; daily exposure composed of 50 unattended calls within 1 hour, each lasting for 45 seconds, followed by a 15-second pause interval before next call
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
SAR 1.58 W/kg - - - according to manufacturer
power density 146.6 µW/cm² peak value measured - 3 cm away from the phone during incoming call
power density 2.109 nW/cm² peak value measured - 3 cm away from the phone in "ON" mode during pause intervals

Reference articles

  • Narayanan SN et al. (2013): Analysis of emotionality and locomotion in radio-frequency electromagnetic radiation exposed rats.
  • Narayanan SN et al. (2010): Effect of radio-frequency electromagnetic radiations (RF-EMR) on passive avoidance behaviour and hippocampal morphology in Wistar rats.

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 level of thiobarbituric acid reactive substances was significantly increased in samples of exposed animals compared to sham exposure and cage control in all investigated brain regions. Moreover, exposure samples showed a significant decrease in the total antioxidative activity in the amygdala and cerebellum but it was not significantly changed in other brain regions. Glutathione S-transferase enzyme activity was significantly decreased in the hippocampus in the exposure group compared to sham exposure and cage control, but it was unaltered in other brain regions studied.
The authors conclude that an exposure of rats to a 900 MHz electromagnetic GSM field causes oxidative stress with regional differences in rat brain, which might be related to behavioral changes observed in Narayanan et al. 2013.

Study character:

Study funded by

Related articles