Study type: Medical/biological study (experimental study)

Pulsed high-frequency electromagnetic field affects human sleep and sleep electroencephalogram med./bio.

Published in: Neurosci Lett 1999; 275 (3): 207-210

Aim of study (acc. to author)

To study whether electromagnetic field emitted by digital cellular phone affects the brain, subjects were exposed during an entire night-sleep episode to an intermittent schedule consisting of alternating 15 minutes "on" and 15 minutes "off" intervals.



Exposure Parameters
Exposure 1: 900 MHz
Modulation type: pulsed
Exposure duration: intermittent, 15 min on/off, for 8 h
  • SAR: 1 W/kg maximum (10 g)

Exposure 1

Main characteristics
Frequency 900 MHz
Exposure duration intermittent, 15 min on/off, for 8 h
Modulation type pulsed
Duty cycle 87.5 %
Repetition frequency 217 Hz
Additional info

The pseudo GSM test signal was modulated with frequencies used by handsets and base stations having components of 2, 8, 217, 1736 Hz.

Exposure setup
Exposure source
Distance between exposed object and exposure source 30 cm
Chamber Two sound insulated and temperature controlled bedrooms with absorber walls placed around the bed to approximate an anechoic room and ensure a relatively uniform exposure.
Setup There was an array of three λ/2 dipole antennas behind each bed at a distance of 30 cm from the head of the recumbent subject. The polarization of the field was perpendicular to the surface of the bed.
Additional info The experiment consisted of two sessions one week apart. EMF or sham exposure was given according to a randomized, placebo controlled, double-blind study, cross-over study design. During an adaptation night per session in a different room, the absorber walls were mimicked by fabric.
Measurand Value Type Method Mass Remarks
SAR 1 W/kg maximum measured 10 g -

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

Compared with a control night the amount of waking after sleep onset was reduced from 18 to 12 min. Spectral power of the EEG in non-rapid eye movement sleep (REM sleep) was increased. The maximum rise occured in the 10.0-11.0 Hz and 13.5-14.0 Hz bands during the initial part of sleep and then subsided. The data demonstrate that pulsed high-frequency electromagnetic field in the range of cellular phones may promote sleep and modify sleep EEG.

Study character:

Study funded by

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