Study type: Medical/biological study (experimental study)

Circadian Rhythmicity of Antioxidant Markers in Rats Exposed to 1.8 GHz Radiofrequency Fields. med./bio.

Published in: Int J Environ Res Public Health 2015; 12 (2): 2071-2087

Aim of study (acc. to author)

The effects of exposure of rats to a 1.8 GHz electromagnetic field on the circadian concentration of melatonin, superoxide dismutase and glutathione peroxidase should be investigated.

Background/further details

The rats were divided into seven groups (n=6 each): daily exposure to the electromagnetic field from 3 to 5 h (group 1), 7 to 9 h (group 2), 11 to 13 h (group 3), 15 to 17 h (group 4), 19 to 21 h (group 5) and 23 to 1 h GMT (Greenwich Mean Time) on the next day (group 6) and sham exposure over 24 h/day (group 7) for 32 days. Subsequently to the last exposure period, blood samples were collected from each rat at 5, 9, 13, 17, 21 h and 1 h GMT on the following day.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 1.8 GHz
Modulation type: CW
Exposure duration: continuous for 2 h/day for 32 days

Exposure 1

Main characteristics
Frequency 1.8 GHz
Type
Charakteristic
Exposure duration continuous for 2 h/day for 32 days
Modulation
Modulation type CW
Exposure setup
Exposure source
Chamber six animals per cage (466 Π315 Π210 mm)
Setup antenna was placed under a table to produce a vertical electromagnetic field in a shielded room; cage was placed on table, roof was hitched with microwave absorbing materials to avoid reflection; all animal handlings during the dark cycle were carried out using a dim red light (0.1 lux)
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
power density 201.7 µW/cm² - measured - -
SAR 0.05653 W/kg mean calculated whole body -
power density 0.001327 W/m² - - - input power density

Reference articles

  • Lopez-Martin F et al. (2008): An experimental Set-Up for measurement of the power absorbed from 900 MHz GSM standing waves by small animals, illustrated by application to Picrotoxin-treated rats.

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

Analysis of the circadian concentrations of the investigated parameters in the sham exposure revealed that there was an independent circadian rhythm in concentration for each parameter.
Significant decreases of the circadian concentration of the parameters were found in all groups compared to the sham exposure, with the most profound and consistent decreases in groups 1 and 6 for melatonin, and in group 1 for superoxide dismutase and glutathione peroxidase. Moreover, the daily mean concentration of all parameters was decreased, most distinctly in groups 1 and 6.
The authors conclude that exposure of rats to a 1.8 GHz electromagnetic field can decrease the circadian concentration as well as the daily mean concentration of melatonin, superoxide dismutase and glutathione peroxidase.

Study character:

Study funded by

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