Study type: Medical/biological study (experimental study)

GSM modulated radiofrequency radiation does not affect 6-sulfatoxymelatonin excretion of rats. med./bio.

Published in: Bioelectromagnetics 2003; 24 (8): 531-534

Aim of study (acc. to author)

To investigate the effect of a GSM radio frequency exposure on 6-sulphatoxymelatonin urinary excretion in rats.

Background/further details

Animals were exposed for 2 weeks (2 h daily) to 900 MHz (power density 100 µW/cm2) or 1800 MHz (power density 20 µW/cm2), modulated at 218 Hz. 6-sulphatoxymelatonin is the major metabolite of melatonin and could easily non-invasive determined in excreted urine.
A total of 72 animals were used in this study. Each experimental setup (i.e. 900 MHz or 1800 MHz) contained 36 animals, divided into 3 subgroups (12 animals each), and each setup was identical repeated three times consecutively. In each subgroup 6 animals were exposed or sham-exposed, respectively, and the obtained data were pooled. Thus, 18 animals were exposed or sham-exposed, respectively, in each experimental setup.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 900 MHz
Modulation type: pulsed
Exposure duration: repeated daily exposure of 2 h/day for 14 days
Exposure 2: 1,800 MHz
Modulation type: pulsed
Exposure duration: repeated daily exposure of 2 h/day for 14 days

Exposure 1

Main characteristics
Frequency 900 MHz
Type
Charakteristic
  • guided field
Exposure duration repeated daily exposure of 2 h/day for 14 days
Modulation
Modulation type pulsed
Repetition frequency 218 Hz
Additional info

Speech was not simulated in the RF signal.

Exposure setup
Exposure source
Chamber The GTEM cell was positioned vertically, and the dominant E-field component was horizontal within the exposure area.
Setup Six freely moving rats were kept in a purely plastic cage of 40 x 30 x 10 cm which was placed over the absorbent material of the GTEM cell at a distance of 0.85 m from the septum. The RF signal was produced by a mobile test phone and a power amplifier.
Additional info The sham exposed control animals were handled just like the exposed ones, but without RF irradiation.
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 19.4 V/m mean measured - ± 2.8 V/m
power density 100 µW/cm² mean measured - at 19.4 V/m
SAR 0.012 W/g - calculated whole body 0.009-0.012 W/kg

Exposure 2

Main characteristics
Frequency 1,800 MHz
Type
Charakteristic
  • guided field
Exposure duration repeated daily exposure of 2 h/day for 14 days
Modulation
Modulation type pulsed
Repetition frequency 218 Hz
Additional info

Speech was not simulated in the RF signal.

Exposure setup
Exposure source
  • TEM cell
  • 2 m high, 1.2 m x 1.2 m floor space
Setup The RF signal was produced by a pulse generator, a signal generator and an amplifier.
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 8.6 V/m mean measured - ± 1.2 V/m
power density 20 µW/cm² mean measured - at 8.6 V/m
SAR 0.045 W/kg - calculated whole body 0.022-0.045 W/kg

Reference articles

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

Neither exposure to 900 MHz nor to 1800 MHz revealed statistically significant changes in the nocturnal excretion of 6-sulphatoxymelatonin in rats compared to sham-exposed control groups.

Study character:

Study funded by

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