The Influence of 50-Hz Electric and Magnetic Fields on Human Cardiovascular Autonomic Function Tests

Abstract

This paper presents a study on the effects of 50-Hz electric and magnetic fields on the human autonomic nervous system. The influence on the autonomic nervous system was studied by cardiovascular autonomic function tests: orthostatic test, Valsalva maneuver, and deep breathing. In the experiments the electrocardiogram and the blood pressure of 41 male volunteers were recorded using ambulatory methods. Twenty-six subjects were measured in and outside real fields and 15 subjects in and outside “sham” fields. Due to rain, eight of the 26 subjects were measured in a tent and these results are not included in this article. In all, the measuring took 3 h. First the subjects spent 1 h outside the field (period 1), then 1 h in the real or “sham” field (period 2), and then again 1 h outside the field (period 3). In periods 1 and 2 the subjects were sitting (0-30 min) and then (31-60 min) the subjects had cardiovascular autonomic function tests: orthostatic test, Valsalva maneuver, and deep breathing.

The electric field strength varied from 3.5 to 4.3 kV/m and the magnetic flux density from 1.4 to 6.6 μT. An analysis of cardiovascular autonomic function tests showed that the subjects' test results were normal 30 min after a 60-min period of exposure. In both subjects exposed to real fields and subjects in sham fields, the results were the same. The results of pulse rate and blood pressure measurements have been presented in other articles. This article deals with the results of cardiovascular autonomic function tests.