Study type: Medical/biological study (experimental study)

Terrestrial Trunked Radio (TETRA) exposure and its impact on slow cortical potentials. med./bio.

Published in: Environ Res 2015; 143 Pt A: 112-122

Aim of study (acc. to author)

The effects of exposure of male subjects to 385 MHz electromagnetic field (TETRA) on the brain activity during wakefulness under cognitive load should be investigated.

Background/further details

3 exposure conditions were tested: exposure to a SAR of 1.5 W/kg, 6 W/kg and sham exposure. In total, 30 male subjects participated in the study. Each subject attended 9 sessions plus 1 training session. One exposure condition was tested at random in each session (so each condition was tested 3 times).
The complete study design comprised daytime and night sessions and further parameters. However, the present paper presents the effects on EEG slow waves during the daytime sessions only, further results are published in Sauter et al. 2015.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 385 MHz
Modulation type: pulsed
Exposure duration: continuous for 2.5 hours
  • SAR: 1.5 W/kg spatial average (10 g) (peak value)
Exposure 2: 385 MHz
Modulation type: pulsed
Exposure duration: continuous for 2.5 hours
  • SAR: 6 W/kg spatial average (10 g) (peak value)

Exposure 1

Main characteristics
Frequency 385 MHz
Type
Waveform
Exposure duration continuous for 2.5 hours
Additional info TETRA
Modulation
Modulation type pulsed
Pulse width 14.17 ms
Duty cycle 25 %
Repetition frequency 17.65 Hz
Exposure setup
Exposure source
Chamber shielded room
Setup TETRA exposure was applied by body-worn antenna with foam spacers and a textile cover, attached to the left ear; subjects were not able to perceive the measurable temperature increases at the skin
Sham exposure A sham exposure was conducted.
Additional info EEG system was battery operated and shielded
Parameters
Measurand Value Type Method Mass Remarks
SAR 1.5 W/kg spatial average measured and calculated 10 g peak value

Exposure 2

Main characteristics
Frequency 385 MHz
Type
Waveform
Exposure duration continuous for 2.5 hours
Additional info TETRA
Modulation
Modulation type pulsed
Pulse width 14.17 ms
Duty cycle 25 %
Repetition frequency 17.65 Hz
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
SAR 6 W/kg spatial average measured and calculated 10 g peak value

Reference articles

  • Dorn H et al. (2014): Experimental investigation of possible warmth perception from a head exposure system for human provocation studies with TETRA handset-like signals.
  • Schmid G et al. (2012): Design and dosimetric analysis of a 385 MHz TETRA head exposure system for use in human provocation studies.

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

There were no significant differences in EEG performance or reaction time found between the exposures.
The authors conclude that there is no evidence for an effect of exposure of male subjects to 385 MHz electromagnetic field (TETRA) on the brain activity.

Study character:

Study funded by

Related articles