VIDEO DISPLAY TERMINALS AND RADON

Recent reports indicate that video display terminals (VDTs) can collec t radon progeny from the air. This occurs' especially when they are tu rned off and may have negative electric fields which attract positivel y charged radioactive dust. We have studied this phenomenon in detail and evaluated various techniques for removing the gettered radioactivi ty while the video display terminal is both off and on. We have evalua ted what happens when the video display terminal is switched, thereby reversing the electric field near the screen. We have also studied pos sible inhalation effects by a video display terminal operator during f ield reversal and find that although some radioactivity may be release d during the cycle, room air currents redistribute it into the room wi th no detectable levels being inhaled by users.