| Electromagnetic fields and radiation are physical phenomena that have surrounded us throughout the whole history of the human race and they can be either natural (produced by the Earth or the Sun, for example) or artificial. Artificial fields are produced by, among others, the following:
Telecommunication devices deliberately produce them, since wireless transmission is achieved through generation of electromagnetic fields that carry the information that we want to transmit over a given distance. The waves containing our information are transmitted by antennas, which are designed to do so in the best way to achieve our ends. Some are designed to broadcast in a certain direction, while others are designed to broadcast in all directions, some broadcast on a single frequency, while others broadcast on several. That is why there are many different types of antenna, each one suitable for given service (radio, television, mobile telephones, emergency services, etc.). A rather wide range of frequencies are used, from kHz to GHz in most cases. The electromagnetic field produced by a telecommunication service can be strong or weak and on one frequency or another, depending on the type of service provided and the distance to be covered.
Electric and electronic devices generate electromagnetic fields unintentionally. This is so because those devices work using internal electric circuits to perform their functions (whether they are espresso machines or computers) and electric current will always generate electromagnetic field. The electromagnetic fields generated by devices are less predictable because they are unintentional and therefore poorly known and difficult to assess theoretically. The frequencies used are as diverse as the range of devices available on the market. The fields generated by electric and electronic devices tend to be weak, given the low levels of power used.
Machinery also generates electromagnetic fields unintentionally, since it uses electric circuits for movement and control. New work safety regulations protect workers from that phenomenon by obliging employers to perform EMF studies and measurements to ensure that those fields are kept within the established limits. In some cases, machinery can generate strong EMFs because of the high levels of power used. The fields generated tend to be at low frequencies, although that is not always the case.
Electrical wiring also generates electromagnetic fields for the simple reason that they carry electric current. This also occurs unintentionally and inevitably, since, as already mentioned, electric current always generates a certain strength of electromagnetic field. The strength of the field generated by electrical wiring can range from undetectable to very strong, depending on whether the current is strong or weak. However, the frequency of the field is limited to the frequency of the grid, which is normally 50/60 Hz.
All those elements, i.e. telecommunications, devices, machinery and wiring, form part of our evolution and progress and make our lives easier, more comfortable and safer: electric light, running water, food preservation, transportation, mobile communication, and so on, the list would be endless. The fact that they generate weaker or stronger electromagnetic fields, being a physical phenomenon, means that they perturb the environment to a greater or lesser extent and any excessive perturbation of the environment can cause health problems. It is important to remember that the services mentioned above generate non-ionising radiation. Ionising radiation is the sort that carries sufficient energy to remove electrons from the atoms of the materials through which it is propagated. We know for certain that ionising radiation is dangerous in strong doses and we also live with it normally, in artificial forms (such as X-rays) and natural forms (sunlight). The effects of non-ionising radiation on the environment and on health have been studied for many years. The leading organisations that have promoted such studies are the ICNIRP (International Commission on Non-Ionising Radiation Protection) and the WHO (World Health Organisation) at the international level, and local organisations such as the European Commission in the EU and the FCC (Federal Communications Commission) and the IEEE (Institute of Electrical and Electronic Engineers) in the US, along with many other local organisations in different countries around the world. As with many other physical phenomena, the crucial factor is the dose received. A given physical phenomenon can be wholly innocuous at low doses but hazardous at high doses. International studies attempt to ascertain the limits for non-ionising radiation so that we can use them safely. The health and environment authorities of many countries have regulated the subject and set the maximum allowable limits depending on services and frequencies. We therefore need to be able to check the electromagnetic fields emitted by such services to ensure that they remain within the limits established as safe by the international health authorities and those of each country. Wavecontrol offers equipment, systems and solutions for measurement and monitoring of non-ionising radiation in electromagnetic fields in order to ensure the safety of people and the environment, so that we do not have to do without them.
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