Navigation and service

High frequency fields

High frequency electromagnetic fields cover the frequency range from 100 kHz to 300 GHz of the electromagnetic spectrum. In general they are distributed by an antenna. They are able to distribute energy and information over a great distance.

Because high frequency electromagnetic fields are used for multiple purposes (e. g. radio and TV broadcast, mobile communication, cordless phones, wireless LAN and bluetooth connections) we are surrounded by a large number of different emitting facilities operating at various transmitting powers and frequencies.

What are high-frequency electromagnetic fields?

Electric and magnetic fields in the frequency range between 100 kilohertz and 300 gigahertz are referred to as high-frequency fields. As electric and magnetic fields are closely coupled at high frequencies, they are also called "electromagnetic" fields.

Effects

High frequency electromagnetic fields are absorbed by biological systems and lead, above all, to a warming of the tissue. The physical basis of this thermal effect is well known and beyond dispute. It is questionable, however, if there are non-thermal biological effects in the region of low intensities of high frequency radiation. Their existence has not been proven up to now but intensive research in this field is going on.

Sources

Numerous technologies use high frequency (HF) electromagnetic fields: Every day life cannot be imagined without broadcasting and television, cordless phones increase comfort when phoning indoors and in the garden, babies are monitored in their rooms using baby monitors, computers are linked to each other and to peripheral devices by using Wireless LAN (WLAN) and Bluetooth and recently ultrawideband (UWB) technologies, police and fire brigades use their own radio network for communication.

Protection

To protect the population from health hazards caused by high-frequency electromagnetic fields from fixed transmitters, the 26th Ordinance on the Implementation of the Federal Immission Control Act (26. BImSchV) sets limit values. The BfS recommends supplementing the limit values with precautionary measures to take into account the scientific uncertainties regarding the health effects of these fields. At certain workplaces, significantly higher exposures to high-frequency electromagnetic fields can occur than are usual and permissible for the general population. There are therefore special regulations for occupational health and safety.

Site information and functions

© Bundesamt für Strahlenschutz