Study type: Medical/biological study (observational study)

Alteration of diurnal rhythms of blood pressure and heart rate to workers exposed to radiofrequency electromagnetic fields. med./bio.

Published in: Blood Press Monit 1998; 3 (6): 323-330

Aim of study (acc. to author)

To determine the course of diurnal rhythms of blood pressure and heart rate in a group of workers exposed to various intensities of radiofrequency electromagnetic fields.

Background/further details

For this study 103 healthy men (aged 28 to 50) were selected. 61 men were exposed and 42 men were non-exposed.



Exposure Parameters
Exposure 1: 0.738–1.503 MHz
Modulation type: AM
Exposure duration: 12 h shift

Exposure 1

Main characteristics
Frequency 0.738–1.503 MHz
Exposure duration 12 h shift
Modulation type AM
Exposure setup
Exposure source
Additional info 103 men aged 28-50 years working at 4 radio broadcasting stations and at 2 radio line stations. All subjects worked in 4 day working cycles with a 12 h day shift, then 24 h rest , a 12 h night shift and 48 h rest. They were 125 shifts per year. 61 subjects from the radio station were considered as exposure group, where as 42 subjects employed at radio line station were considered as unexposed group.
Measurand Value Type Method Mass Remarks
electric field strength 200 V/m - measured - to 550 V/m; 23 subjects
electric field strength 20 V/m - measured - to 180 V/m; 38 subjects

Reference articles

  • Bortkiewicz A et al. (1995): Dysregulation of autonomic control of cardiac function in workers at AM broadcasting stations (0.738 - 1.503 MHz) .

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

The subjects of the control group exhibited typical, well-preserved diurnal rhythms of blood pressure and heart rate with two maxima (at about 14:00 and 17:00-18:00 h) and one minimum (at about 2:00-4:00 h).
For workers exposed to radiofrequency electromagnetic field a significant lowering of the amplitudes of rhythms of blood pressure and heart rate and a shift of the acrophase to an earlier time (11:00-12:00 h) were observed. These changes were more pronounced among workers exposed to high intensities of radiofrequency electromagnetic field.
The clinical relevance of the present finding needs to be investigated in further studies.

Study character:

Study funded by

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