Devices generating electromagnetic fields in the radio frequency (RF) range (from 100 kHz to 300 GHz) are in widespread use in our society. Key sources of RF fields include mobile phones, cordless phones, local wireless networks and radio transmission towers. They are also used by medical scanners, radar systems and microwave ovens.
Information about the strength of radio frequency fields generated by a given source is readily available and useful in determining compliance with safety limits. But little is known about the exposure of individuals to radio frequency fields, data that are crucial for studies of health effects. Knowledge could be increased through better use of methods such as exposimeters, devices carried by individuals to measure their exposure to electromagnetic energy over time. It is furthermore important to consider multi-source exposure and not to focus on single sources, e.g. mobile phone base stations.
The fact that there is a continuous change of technologies, e.g. from analogue to digital TV, and an emergence of new technologies like ultra-wide band (UWB) on the market, leads to changing exposure patterns of the population on a long term scale.
Sources of radio waves operate in different frequency bands, and the strength of the electromagnetic field falls rapidly with distance. Over time, a person may absorb more RF energy from a device that emits radio signals near the body than from a powerful source that is farther away. Mobile phones, cordless phones, local wireless networks and anti-theft devices are all sources used in close quarters. Long-range sources include radio transmission towers and mobile phone base stations.
More than 2.5 billion people use mobile phones worldwide. Most mobile communication in Europe uses either GSM or UMTS technology. The European Union has set safety limits on the energy absorbed by the body from exposure to a mobile phone. Mobile phones sold in Europe must undergo standardised tests to demonstrate compliance in accordance with the specifications of the European Committee for Electrical Standardization (CENELEC).
Sierra Leone, Freetown
Croatia (Hrvatska), Zagreb
Amarillo, Texas, USA
Click on any of the pictures below
to learn more