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Electromagnetic fields

Mobile communication, WLAN & Co. - Grid expansion - Household appliances & electric installations

Elektromagnetische Felder

What are static and low frequency electric and magnetic fields?

Electric and magnetic fields are force fields. The direction and strength of a field can be visualised as field lines: The density of the lines symbolises the field strength. As opposed to electric field lines - which start and end at electric charges, magnetic field lines are closed.

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Household appliances & electrical installations

Low-frequency electric and magnetic fields are generated by household appliances and electrical installations in the home. In Germany the safety of equipment is regulated by product standards that are based on the product safety law. If these standards assess possible health effects of electric and magnetic fields, the assessment is based on the limits recommended by the Council of the European Union .

Effects of static fields

Static magnetic fields exert forces on magnetisable metals as well as on moving electrically charged particles. As an example humans use strong magnetic fields for medical imaging methods. To date, investigations have not revealed any direct negative biological or health effects from static magnetic fields with magnetic flux densities of up to four teslas. Further research is needed on the effects of stronger static magnetic fields.

Direct and alternating voltage

A basic distinction is made between direct and alternating voltage or, as the case may be, between direct and alternating current. Alternating voltage changes the polarity of the connections at regular intervals, in other words, the negative pole turns into the positive pole and vice versa. When a current flows, the electrons forming the current change their direction of flow accordingly. With direct voltage and current, the polarity and the direction of flow of the electrons are not reversed.

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Display screens

Just like any other electrical office or household equipment, television and computer screens generate low-frequency electric and magnetic fields. These are mainly alternating electric and magnetic fields with a frequency of 50 Hz, which is the regular power supply frequency.

Precaution

According to current scientific knowledge, the protection of the health of the population is also ensured under permanent exposure by compliance with the limit values set in the Twenty-sixth Ordinance Implementing the Federal Immission Control Act (Ordinance on Electromagnetic Fields - 26th BlmSchV). However, apart from proven health effects there exists scientific evidence of health risks at low field intensities. In order to account for this uncertainty the Federal Office for Radiation Protection demands precautionary measures.

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