Study type: Medical/biological study (experimental study)

No effects of pulsed high-frequency electromagnetic fields on heart rate variability during human sleep. med./bio.

Published in: Neuropsychobiology 1998; 38 (4): 251-256

Aim of study (acc. to author)

The effects of pulsed high-frequency electromagnetic fields in the lower microwave frequency range generated by a digital mobile phone on heart rate variability during sleep were investigated.

Background/further details

The relation between low frequency and high frequency components of heart rate variability represents the balance between the two branches of the autonomic nervous system. The high frequency component reflecting sinus arrhythmia, has been attributed to the modulation of the parasympathetic output. The low frequency component has been referred to both sympathetic and parasympathetic activity.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 900 MHz
Modulation type: pulsed
Exposure duration: continuous for 8 h

General information

The experimental design was identical to the previous study detailed in the reference article.

Exposure 1

Main characteristics
Frequency 900 MHz
Type
Exposure duration continuous for 8 h
Modulation
Modulation type pulsed
Pulse width 577 µs
Repetition frequency 217 Hz
Exposure setup
Exposure source
Distance between exposed object and exposure source 40 cm
Setup The mobile phone was positioned at a distance of 40 cm to the vertex with the antenna axis perpendicular to the axis of the subject's body.
Additional info After an adaptation night, polysomnographies were performed during two successive nights. Each subject was exposed to the EMF in one night and not exposed in the other night (randomized and blinded).
Parameters
Measurand Value Type Method Mass Remarks
power density 0.05 mW/cm² mean - - at 40 cm

Reference articles

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

Under these experimental conditions, the autonomic control of heart rate was not affected by weak high frequency electromagnetic fields emitted by digital mobile phones.
For most parameters, significant differences between different sleep stages were revealed. In particular, slow wave sleep was characterized by a low ratio of low frequency and high frequency components, indicating a predominance of the parasympathetic over the sympathetic tone. In contrast, during REM sleep the autonomic balance was shifted in favor of the sympathetic activity. For all heart rate parameters, no significant effects were detected under exposure compared to sham exposure.

Study character:

Study funded by

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