Study type: Medical/biological study (experimental study)

An investigation of the effects of TETRA RF fields on intracellular calcium in neurones and cardiac myocytes. med./bio.

Published in: Int J Radiat Biol 2005; 81 (12): 869-885

Aim of study (acc. to author)

To determine whether Terrestrial Trunked Radio (TETRA) fields can affect intracellular calcium signalling in excitable cells.

Background/further details

Cultured rat cerebellar granule cells and cardiac myocytes were loaded with the calcium-sensitive fluorescent probes fura- PE-3, fluo-3 (granule cells), and fluo-4 (cardiac myocytes).
The TETRA communication system incorporates a pulsed modulation at 17.6 Hz, very close to the 16 Hz modulation which has been reported to enhance calcium efflux (publication 309 and publication 8142).

Endpoint

Exposure

Exposure Parameters
Exposure 1: 380.8875 MHz
Modulation type: pulsed
Exposure duration: continuous for 20 min
  • SAR: 400 mW/kg average over mass (10 g) (320-480 mW/kg)
Exposure 2: 380.8875 MHz
Modulation type: pulsed
Exposure duration: consecutive levels for a total of 40 min
  • SAR: 5 mW/kg average over mass (10 g)
  • SAR: 10 mW/kg average over mass (10 g)
  • SAR: 20 mW/kg average over mass (10 g)
  • SAR: 50 mW/kg average over mass (10 g)
Exposure 3: 380.8875 MHz
Modulation type: pulsed
Exposure duration: continuous for 11 min
  • SAR: 400 mW/kg average over mass (10 g) (320-480 mW/kg)
  • SAR: 50 mW/kg average over mass (10 g)

Exposure 1

Main characteristics
Frequency 380.8875 MHz
Type
Exposure duration continuous for 20 min
Modulation
Modulation type pulsed
Duty cycle 25 %
Repetition frequency 17.6 Hz
Exposure setup
Exposure source
Setup Cells were exposed to TETRA RF fields in a perfusion chamber mounted on the stage of an inverted microscope within a stripline parallel-plate transmission line. The exposure system that is depicted with measures in a figure, was similar to that described in the reference article, but adapted to fit the stage of the inverted microscope. TETRA RF waveforms were provided by a function generator and an amplifier. The output waveform from the signal generator comprised an allocated frequency of 380.8875 MHz modulated according to the ETSI standard, to simulate that of in-service hand-sets. A directional coupler and power meter were used to monitor forward and reverse power. For exposures, the RF signal was fed into the transmission line and terminated (50 W termination). For sham exposures, the RF signal was fed directly into the termination, thus bypassing the transmission line. Cell cultures were randomly assigned to exposed or sham groups.
Parameters
Measurand Value Type Method Mass Remarks
SAR 400 mW/kg average over mass measured and calculated 10 g 320-480 mW/kg

Exposure 2

Main characteristics
Frequency 380.8875 MHz
Type
Exposure duration consecutive levels for a total of 40 min
Modulation
Modulation type pulsed
Duty cycle 25 %
Repetition frequency 17.6 Hz
Exposure setup
Exposure source
Setup In order to investigate the effects of exposure intensity, cell cultures were exposed for consecutive 10-min periods to baseline and TETRA RF fields at 5, 10, 20 and 50 mW/kg.
Parameters
Measurand Value Type Method Mass Remarks
SAR 5 mW/kg average over mass measured and calculated 10 g -
SAR 10 mW/kg average over mass measured and calculated 10 g -
SAR 20 mW/kg average over mass measured and calculated 10 g -
SAR 50 mW/kg average over mass measured and calculated 10 g -

Exposure 3

Main characteristics
Frequency 380.8875 MHz
Type
Exposure duration continuous for 11 min
Modulation
Modulation type pulsed
Duty cycle 25 %
Repetition frequency 17.6 Hz
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
SAR 400 mW/kg average over mass measured and calculated 10 g 320-480 mW/kg
SAR 50 mW/kg average over mass measured and calculated 10 g -

Reference articles

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • before exposure
  • during exposure
  • after exposure

Main outcome of study (acc. to author)

The data showed no evidence of any consistent or biologically relevant effect of TETRA fields on intracellular calcium in granule cells and cardiac myocytes at any of the SAR tested.

Study character:

Study funded by

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