Static fields (0 Hz)

The main effects of static fields are electric and/or magnetic force effects, which affect electrically charged inner and outer body structures mechanically or via magnetic induction. In this respect, these fields can also induce the movement of electrical charges (e.g. ions or surface charges), which can cause polarization, charging effects and electrical discharges on microscopic and macroscopic scales.

Static electric fields

If static electric fields are strong enough, the electrical charge of the skin surface is perceptible due to micro-discharges and the movement of hairs, which repel each other and then straighten up. The human sensing threshold is stated in a range from 10 to 45 kV/m (ICNIRP). The only relevant direct health effect of static electric fields known is the possible stress caused by prolonged exposure to microshocks. However, so far no harmful effects could be detected in human and animal laboratory studies (ICNIRP). No direct effects occur inside the body because static electric fields discharge at the surface due to the high conductivity of the body and cannot penetrate the body.

Static magnetic fields

In contrast to static electric fields, static magnetic fields penetrate most materials - including the body tissue - very well and can potentially take effect at any point within the body. Magnetic fields interact with moving charge carriers (e.g. ions in cells and body fluids, charges on cell surfaces or electrically charged cells in the blood) and can produce electric fields and currents via induction. This can cause perceptible but harmless effects (e.g. temporary symptoms like vertigo, nausea or metallic taste) in cases of very high magnetic flux densities (2-3 T or more, e.g. used in magnetic resonance imaging). If a subject moves in strong static magnetic fields this can also lead to interactions and the generation of inner electric fields and currents via induction (see chapter Low frequency (0.1 Hz–1 kHz)).

Generally, the effects of static electric and magnetic fields decrease with increasing distance to the field source.