EMF/ ELF Sources

Electricity supply systems, electrical appliances and a wide range of transmitters for various wireless applications generate non-ionising radiation (commonly referred to as “electrosmog”) that can be harmful to our health, depending on its intensity. With its Ordinance relating to Protection from Non-Ionising Radiation, the Federal Council introduced a legal instrument to protect the population against the harmful effects of electrosmog. We describe the main sources of electrosmog, assess the associated risks, identifies existing gaps in research and suggests ways in which we can reduce our own level of exposure.

Power supply- Electric and magnetic fields are unavoidable by-products of electricity transmission and use. The highest levels of exposure occur in the immediate vicinity of high-voltage power lines and transformer stations.

Transformer room - A transformer is a static electrical device that transfers energy by inductive coupling between its winding circuits. A varying current in the primary winding creates a varying magnetic flux in the transformer core and thus a varying magnetic flux through the secondary winding. This varying magnetic flux induces a varying electromotive force (emf) or voltage in the secondary winding. Transformers can be used to vary the relative voltage of circuits or isolate them, or both.

High voltage line- Dolev active magnetic shielding systems are used primarily for reducing power line magnetic fields. They are effective for both transmission and distribution lines, overhead and underground. Within a defined area, the magnetic field can often be reduced to a very low level. Active shielding is usually the only practical approach to power line field mitigation at the whole-building level.



Simulation - There are situations when direct measurement of field strengths, no matter how thoroughly or competently performed, are inadequate to the analytical requirements. In other cases, like this direct measurement are impossible - the facilities do not yet exist. At such times, analysis by computer model is necessary: The purpose of the simulation is to examine the electric & magnetic field levels, after the Implementing of the Electrical facility.

Electrical appliances in the home-In most residential dwellings, electrosmog is home-made. Here we ourselves are able to considerably reduce our level of exposure by taking basic measures. For example, we should avoid placing electrical appliances that run constantly, e.g. clock radios, in places where people spend
lengthy periods of time.

How fields are created?
Everyday we use electrical appliances and devices at home, at work and in our leisure time. And wherever electricity is used, electric and magnetic fields are created – for example in close proximity to high-voltage power lines, sub-stations and transformer stations. But these fields are also created by electrical appliances in households, offices, factories, etc.
Electric fields occur as soon as an appliance is connected to the power supply via a cable and plug. As soon as it is switched on, current begins to flow, and this gives rise to a magnetic field in addition to the already existing electric field. Since our power supply is operated with alternating current with a frequency of 50 Hz, the electric and magnetic fields are also 50 Hz alternating fields.
Some of the properties of electric and magnetic fields are similar: for example, in both cases they weaken rapidly with increasing distance from the source. However, they differ greatly when it comes to screening: electric fields can be screened fairly easily, whereas magnetic fields freely penetrate practically all materials, and screening is therefore only possible with the aid of special metal alloys or thick aluminium sheets, and even then only to a limited extent.