The electromagnetic pollution is composed of the electric and magnetic fields which are present in our environment and which are not of natural origin. Electric fields are measured in volt/metre (V/m) and increase their intensity according to the electric voltage which generates them.

More the power of a domestic appliance is strong, more the electric field will be strong too. Magnetic fields are produced by different electric fields or electric currents. They are measured in ampere/metre and are proportional to the strength of the current which inferred them and thus, in the electricity consumption of the electric devices which generate them (Example: TV with cathode ray tube and LCD screen).

Electromagnetic fields and waves are composed of a sinusoidal electric field coupled with another sinusoidal magnetic field. They become inseparable and we speak then about electromagnetic fields. This electromagnetic field propagates in the environment at the speed of light by forming the electromagnetic waves.

It produces an electromagnetic strength which is the sum of the electric strength of the electric field and the magnetic strength of the magnetic field. The electromagnetic waves are characterized by 3 parameters strictly connected which allow to classify them and which also determine their technological use and their impact on the environment:

• The wave-length, measured in metres.
• The frequency, measured in Hertz (Hz), is the number of wave-lengths included in one second (For instance: radio frequency).
• The energy which they transport and can pass on in the objects that they meet, measured in Joules (J) or in electrons-volts (eV).

To estimate the impact on the health, we rather use the flow of specific absorption in Watt/kg}, it is the new compulsory measure for mobile phone activity. It must be lower than 2 DAS. It is new obligatory measurement for mobile telephony. It must be lower than 2 DAS for mobile phones.

The electric and magnetic fields with very low frequency, also called ELF Fields for "Extremely Low Frequency", coexist in the environment of any working device or electric line, while only electric fields are present around a put out but connected device.

ELF Fields generally entail only a low energy absorption and no rise of measurable temperature.
The radio frequencies and the hyper frequencies are due to telecommunications, video screens, a few medical or domestic equipments and many industries.

Many studies are carried out to estimate their degree of harmfulness on human beings.