Occupational exposure to radio frequency fields
In close proximity to high power transmitters such as radar and radio installations, field strengths can be so high that they cause the body, or at least parts of it, to heat up. Because of this, radio and radar installations have a closed safety areas. Working in these types of areas is dealt with in STUK’s ST directives 9.2 ‘Radiation Safety of Pulsed Radars’ and 9.3 ‘Radiation Safety during Work on Masts at FM and TV Stations’.
Users of industrial high frequency heaters are exposed to the most intense electric and magnetic fields. However, users of such machinery as high frequency plastic welders or radio frequency dryers, for example, have not been shown to have health problems which are clearly a result of radio frequency electric or magnetic fields. To be on the safe side, however, pregnant women should avoid working with machinery that radiates strongly.
In recent years, microwave dryers have been used to repair damage from damp in concrete. If misused, these devices might be dangerous. Especially the eyes are at risk; in just a few minutes the powerful microwave radiation can cause damage to them. When this type of device is in use, it must be ensured that the area is clear of non-essential workers and that nobody is behind the surface to be repaired.
