Study type: Medical/biological study (experimental study)

Pulsed radio-frequency electromagnetic fields: dose-dependent effects on sleep, the sleep EEG and cognitive performance. med./bio.

Published in: J Sleep Res 2007; 16 (3): 253-258

Aim of study (acc. to author)

To establish a dose-response relationship between the field strength of electromagnetic fields and previously reported effects (see "Related articles") on the brain, the authors aimed to investigate the influence of electromagnetic field exposure by varying the signal intensity (0.2 W/kg; 5 W/kg; sham exposure).

Background/further details

The heads of 15 healthy male subjects was unilaterally exposed for 30 min prior to sleep. During exposure subjects performed cognitive tasks. Immediately after exposure, night-time sleep was polysomnographically recorded for 8 h.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 900 MHz
Modulation type: pulsed
Exposure duration: continuous for 30 min
  • SAR: 0.2 W/kg average over mass (10 g)
  • SAR: 5 W/kg average over mass (10 g)

General information

The study consisted of three sessions separated by 1-week intervals in a randomized double-blind crossover design. Each session consisted of an adaptation night and a subsequent experimental night.

Exposure 1

Main characteristics
Frequency 900 MHz
Type
Exposure duration continuous for 30 min
Modulation
Modulation type pulsed
Pulse width 0.577 ms
Duty cycle 21 %
Additional info

GSM-like handset signal (DTX and non-DTX without temporal switching) [Huber et al., 2005] with modulation components of 2, 8, 217 and 1736 Hz and higher harmonics

Exposure setup
Exposure source
Setup Subjects were exposed unilaterally (left hemisphere) with their heads positioned between two plates to ensure a well-defined position with respect to the planar antennas [Huber et al., 2000, 2003].
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
SAR 0.2 W/kg average over mass - 10 g -
SAR 5 W/kg average over mass - 10 g -

Reference articles

  • Huber R et al. (2005): Exposure to pulse-modulated radio frequency electromagnetic fields affects regional cerebral blood flow.
  • Huber R et al. (2003): Radio frequency electromagnetic field exposure in humans: Estimation of SAR distribution in the brain, effects on sleep and heart rate.
  • Huber R et al. (2000): Exposure to pulsed high-frequency electromagnetic field during waking affects human sleep EEG.

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

Sleep architecture was not affected by electromagnetic field exposure. The sleep EEG revealed a dose-dependent increase of power in the spindle frequency range in non-REM sleep.
Reaction speed decreased with increasing field strength in the 1-back task, while accuracy in the 2-choice reaction time task and N-back task were not affected in a dose-dependent manner.
In conclusion, the data revealed first indications of a dose-response relationship between electromagnetic field intensity and its effects on brain physiology.

Study character:

Study funded by

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