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2 US Military Definition |
There are essentially three major potential hazards associated with electromagnetic radiation:
Strong electromagnetic fields can generate an electric current in other metal objects by electromagnetic induction. The induced current can cause an electric shock to persons or animals. It can also overload and destroy electrical equipment. This can be a particular hazard in the vicinity of military ordnance, since an electrical overload can cause ordnance to discharge or explode.
Again by electromagnetic induction, a strong electromagnetic field can cause electric currents which may flow across an air gap to ground, causing sparks. These sparks can then ignite flammable materials or gases, possibly leading to an explosion or a fire.
The main biological effect of electromagnetic fields is to cause heating. For example, touching an antenna while a transmitter is in operation can cause severe burns. Birds sitting on very high-power antennas when transmission begins can be instantly cooked by RF energy. In fact, that is the principle behind the operation of a microwave oven.
This heating effect varies with the frequency of the electromagnetic energy. The eyes are particularly vulnerable to RF energy in the microwave range, and prolonged exposure to microwaves can lead to cataracts. Each frequency in the electromagnetic spectrum is absorbed by living tissue at a different rate, called the specific absorption rate or SAR, which has units of watts per kilogram (W/kg). The IEEE and many national governments have established safety limits for exposure to various frequencies of electromagnetic energy based on SAR.
Types of Hazard
Electrical Hazards
Fire Hazards
Biological Hazards
US Military Definition