DAILY VARIATION OF THE RADON CONCENTRATION INDOORS AND OUTDOORS AND THE INFLUENCE OF METEOROLOGICAL PARAMETERS

Series of continuous radon measurements in the open atmosphere and in a dwelling, including the parallel measurement of meteorological param eters, were performed over a period of several weeks. The radon concen tration in indoor and outdoor air depends on meteorological conditions . In the open atmosphere the radon concentration varies between 1 and 100 Bq m(-3), depending on weather conditions and time of day. During time periods of low turbulent air exchange (high pressure weather with clear night sky), especially in the night and early morning hours (ni ght inversion layer), the diurnal variation of the radon concentration showed a pronounced maximum. Cloudy and windy weather conditions yiel d a small diurnal variation of the radon concentration. Indoors, the a verage level and the diurnal variation of the indoor radon concentrati on is also influenced by meteorological conditions. The measurements a re consistent with a dependence of indoor radon concentrations on indo or-outdoor pressure differences.