What are electromagnetic fields?

Electromagnetic fields consist of electric and magnetic fields. They are created when electric currents and tensions change, forming an electromagnetic wave that spreads. This wave transports energy.

Electromagnetic fields are part of nature. For example, they are present in daylight and flashes of lightning during thunderstorms. Other fields are created by electronic devices and installations because electromagnetic fields form around every electric current. Televisions, hair driers, CD players or electric shavers all create such fields.

The electromagnetic spectrum

Electromagnetic fields differ in their frequency, field strength and electromagnetic wave signals. Within the electromagnetic spectrum, frequency fields may be high-frequency or low-frequency. High-frequency electromagnetic fields range from 10 kilohertz (KHz) to 300 gigahertz (GHz). They are used by radio and television stations; radio systems, such as those for emergency medical services and taxis, or radio-controlled anti-theft devices. Low-frequency electric and magnetic fields of between 0 hertz (Hz) and 10 kilohertz (KHz) are created in power generation and transmission and in homes, with frequencies of around 50 hertz (Hz).

1 hertz is 1 cycle per second

1 megahertz is 1 million hertz

1 gigahertz is 1,000 million hertz

Mobile networks use high-frequency electromagnetic fields to transmit speech and data. Currently, the three most common mobile communications standards are GSM (Global System for Mobile Communications), UMTS (Universal Mobile Telecommunications System) and the new LTE (Long Term Evolution). They all use different frequency ranges: GSM – 900 to 1,800 MHz, UMTS – 1,900 to 2,170 MHz and LTE – 800 to 2,600 MHz.

The electromagnetic fields produced by mobile communications are fields with non-ionizing electromagnetic radiation. Radio waves, microwaves and optical radiation also fall into this category. One important characteristic of this type of radiation is that it does not carry enough energy to ionize atoms or molecules (i.e., to produce charged ions) when passing through matter. Only ionizing radiation, such as x-rays and gamma rays, carries these levels of energy.

What about “electronic smog”?

Electronic smog is another term encountered in connection with electromagnetic fields, as used by mobile communications. Even though it is widely used in public discussion, this term is not quite accurate. Smog usually refers to a certain concentration of pollutants in the air. Therefore, with regard to the electromagnetic fields of mobile communications, this term is misleading as these fields do not spread in the same way as soot particulates from exhaust fumes. Furthermore, they are not a waste product but a prerequisite for transmission in mobile communications.