mobile telephony and health

What is an electromagnetic field?

Mobile telephony is just one of many applications of electromagnetic waves. Depending on the frequency of their oscillations, they have different properties which can be used in technical applications. In addition to electromagnetic fields created by humans, there exist other, natural sources. In fact, we’re always immersed in an electromagnetic field.

The sun, radio and TV transmitters, home appliances, computer monitors, the power grid, all generate electromagnetic waves, and these are just a few of the potential sources. Aeroplanes are guided using such waves, ambulances, the fire service and the police communicate using them. Mobile telephony is relatively recent, as it became operational at the beginning of the 1980s. However, in the meantime other technologies have already been introduced which use electromagnetic fields, such as Wi-Fi or Bluetooth, and their evolution isn’t going to stop here.

Electric current and electric charge generate magnetic and electric fields. The two are generally interlinked, and when they oscillate together they generate an electromagnetic wave which moves through space. This is where the term electromagnetic field comes from.

Depending on the frequency of the oscillation, two broad categories can be identified: ionising and non-ionising waves. Ionising waves (ultraviolet rays, X-rays, Gamma rays etc.) are very high-energy and can have negative effects on biological organisms, causing DNA mutations. That's why this type of electromagnetic radiation is used with great caution. In fact, the terms “radiation” and “radioactivity” generally refer to ionising electromagnetic waves.

Non-ionising waves don’t contain enough energy to cause ionisation and change the structure of matter. They have certain properties which have allowed us to develop the technical applications that we use in our everyday lives. We’ve had radio and television transmitters, power cables, home appliances, radio navigation systems, dedicated communication systems for ambulance, fire and police services, the military, television sets and computer monitors for decades. All these generate electromagnetic fields, which we are exposed to permanently.

Mobile telephony is one of the newer applications of non-ionising waves, given that the first mobile phone network went into service at the beginning of the 1980s. It isn’t, however, the very latest technical application of electromagnetic waves. Local radio networks (Wi-Fi), metropolitan radio networks (WiMAX, HiperLAN), personal networks (Bluetooth) are just some of the technologies which have been developed more recently, and the evolution isn’t going to stop here.