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Electromagnetic fields, even though invisible, are present everywhere and in every home appliance that we use. These Electro Magnetic Fields are set up where ever current and power is available. Usage of mobile phones emits signals which are a form of Electro Magnetic Radiations. Even though all the appliances are helpful for the comfort of humans, they also cause harmful effects.
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The Electro Magnetic Fields:
Electricity is used everywhere and in every work that we perform in day to day life. Let it be cooking in kitchen or rocket propulsion, without electricity, nothing is possible these days. Associated with electricity, we also have some thing called as Electro Magnetic Fields (EMF), which arise when ever electrical energy is used. The EMFs are present around all wires carrying electricity.
The strength of this magnetic field depends upon the amplitude of current that is flowing, while the amplitude of the current depends upon the voltage applied. One important thing which is to be noted is electric fields are easily shielded, whereas magnetic fields are not. Thus the strength of the electric and magnetic field is an important factor upon which the health of the person is dependant.
It is unknown to many people that Electro Magnetic Fields interact with a human body. But it is very complex to explain such EMF interactions as it varies with the frequency ranges. If a human body is exposed to such EMFs, the energy is absorbed by the body and thus creates small, very weak, internal electric fields. The amount of energy absorbed depends on the various factors such as the type of radiation source, distance between the human and the radiation source, and many other factors including the physical characteristics like height etc. The extent of EMF interaction is expressed in terms of dosimetric quantities. These dosimetric quantities specifications are extremely important in providing the relationship between the EMFs and health effects.
The above picture shows the various classifications of EMF frequencies and their typical applications. Even though various researches are being carried out everyday to find out exactly the effects of EMFs, there are no concrete evidences of health effects. However these are some of the reported and most encountered health effects because of the interaction with the electromagnetic field.
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These are often experienced as static electric shocks due to the accumulation of charges on the human body. These effects happen for a frequency of EMF, which is below 100 kHz. The built up of charges on human body (eg: on hairs), gets excited and rises up. These accumulate and get discharged when any earthed metal is touched. Thus these may be termed as micro-shocks, where they directly does not affect any human being, but indirectly may cause loss of concentration or falls, trips etc.
Effects on Central Nervous System:
When the EMF frequency is less than 100 kHz, at times, the EMFs may interact with the central nervous system, thus causing interference in signals between the brain and the limbs. These could result in temporary or permanent loss in movement of limbs, visual process etc.
If the EMF frequencies are more than 100 kHz, then depending upon the frequency and the field strength, the body suffers from partial body or whole body heating. However, these does not happen in normal circumstances, unless any incidents/accidents in power plants or transformer stations. Sometimes, the body suffers overload of the thermoregulatory system resulting in heat stroke.
RF Shocks and Burns:
A typical example would be getting a shock from a RF charged capacitors or any conductors. Sometimes the shock would result in deep, very severe burns and may take time to heal.
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Even though EMF are present everywhere, from every household appliance that we use, in addition to help humans, they also affect the health and well-being. There also certain precautions that are to be taken by the employees who are working in Electrical sub-stations as the strength and frequency of the EMF are comparatively high. In my next article, we will discuss the precautions that are necessary when being exposed to EMF areas.