Electromagnetic fields and radiation surround us everywhere. Just click the switch - and the light comes on, turn on the computer - and you are on the Internet, dial the number on your mobile phone - and you can communicate with distant continents. In fact, it was electrical appliances that created the modern world as we know it. Recently, however, the question has been raised more often that electromagnetic fields (EMFs) generated by electrical equipment are harmful. Is it so? Let's try to figure it out.
Let's start with the definition. Electromagnetic fields, as is known from the school physics course, are a special kind of matter. A key feature of such fields is the ability to interact in a certain way with bodies and particles that have an electric charge. As the name implies, electromagnetic fields are a combination of magnetic and electric fields, and in this case they are so closely interconnected that they are considered a single whole. Features of interaction with charged objects are explained using the Lorentz force.
For the first time, electromagnetic fields were mathematically expressed in Maxwell's theory in 1864. Actually, it was he who revealed the indivisibility of magnetic and electric fields. One of the consequences of the theory was the fact that any disturbance (change) in the electromagnetic field is the cause of the appearance of electromagnetic waves propagating in vacuum at the speed of light. Calculations showed that light (all parts of the spectrum: infrared, visible, ultraviolet) is precisely an electromagnetic wave. In general, classifying radiation by wavelength, distinguish x-ray, radio, etc.
The advent of Maxwell's theory was preceded by the work of Faraday (in 1831) on the study of electromagnetic induction in a conductor moving or in a periodically changing magnetic field. Even earlier, in 1819, H. Oersted noticed that if a compass was placed next to a current-carrying conductor, its arrow deviates from the Earth’s natural magnetic pole, suggesting a direct connection between magnetic and electric fields.
All this indicates that any electrical appliance is an electromagnetic wave generator. This property is especially pronounced for some specific devices and high current circuits. Both the first and second are now present in almost every home. Since EMF is distributed not only in conductive materials, but also in dielectrics (for example, vacuum), a person is constantly in the zone of their action.
If before, when the room was only “Ilyich’s bulb”, the question didn’t bother anyone. Now everything is different: the measurement of the electromagnetic field is carried out using special instruments for measuring the field strength. Both components of the EMF are fixed in a certain frequency range (depends on the sensitivity of the device). The document SanPiN indicates PDN (permissible norm). At enterprises and large companies periodically checks PDN EMF. It is worth noting that there are still no final results of studies of the effects of electromagnetic fields on living organisms. Therefore, for example, when working with computer technology, it is recommended to organize 15-minute breaks after each hour - just in case ... Everything is explained quite simply: there is a magnetic field around the conductor, which means that there is also an electromagnetic field . The equipment is completely safe when the power cord is unplugged from the outlet.
Obviously, few will dare to completely abandon the use of electrical equipment. However, you can additionally secure yourself by connecting home appliances to a grounded network, which allows the potential not to collect on the case, but to "drain" into the ground loop. Various extension cords, especially wound into rings, reinforce EMF due to mutual induction. And, of course, close placement of several switched on devices at once should be avoided.