Influence of 50-Hz electric and magnetic fields on human blood pressure

This investigation studied the effects of 50-Hz electric and magnetic fields on the pulse rate and blood pressure in humans. Electrocardiograms (ECG) 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. The results of the ECG recordings have been presented earlier. This article deals with the analysis of the blood pressure measurements. Measurement took 3 hrs. First, the subjects spent 1 h outside the fields, then 1 h in real or "sham' fields, followed by 1 h outside the fields. The electric field strength varied from 3.5 to 4.3 kV/m and the magnetic flux density from 1.4 to 6.6 microT. When analysing the blood pressure, which was measured with a noninvasive cuff method, it could not be shown that the fields (< 4.3 kV/m and < 6.6 microT) affected diastolic or systolic blood pressure.