Video display terminals and radon.
Recent reports indicate that video display terminals (VDTs) can collect radon progeny from the air. This occurs especially when they are turned off and may have negative electric fields which attract positively charged radioactive dust. We have studied this phenomenon in detail and evaluated various techniques for removing the gettered radioactivity while the video display terminal is both off and on. We have evaluated what happens when the video display terminal is switched, thereby reversing the electric field near the screen. We have also studied possible inhalation effects by a video display terminal operator during field reversal and find that although some radioactivity may be released during the cycle, room air currents redistribute it into the room with no detectable levels being inhaled by users.
Evaluation of the DC electrical environment in proximity to VDTs
Abstract Two VDTs were tested to determine their impact on the DC electrical environment. Characteristics of the DC environment were measured — ion concentration, ion current density and DC electric field. Measures of particulate levels, temperature and humidity were included since these factors are known to influence the DC environment. Ion concentrations, especially negative ion concentrations, varied as a function of distance from the VDTs, with the lowest values observed in the immediate vicinity of the VDTs for both models tested. This effect was slight and within the range of expected indoor values for ion concentrations. DC electric fields were generally found to be higher during VDT operation compared to controls, although they were within the same order of magnitude as commonly experienced fields due to charges on materials (e.g. clothing, carpet) indoors. Particulate levels were not observed to be altered by VDT operation.
The development of a liquid antihistaminic preparation with sustained release properties.
The relative capacity of several cation exchange resins to adsorb methapyrilene has been determined by an in vitro method. It was demonstrated that methapyrilene adsorbed on sulfonic acid cation exchange resin possessed pharmacological activity approximating that of a solution of methapyrilene hydrochloride as measured by the protection against histamine-induced asthma in the intact guinea pig. It is suggested that the use of ion exchange resins as carriers of drugs in liquid dosage forms may be useful in sustained release preparations.