Variability of radon activity concentration in soil gas due to changes in groundwater table and meteorological parameters - first results of a continuous long term radon monitoring abstract

The evaluation of the geogenic radon potential is based on field measurements of radon activity concentration in soil gas. The values obtained through such spot measurements depend strongly on the geological background [1] [2] but also on the soil properties like grainsize distribution, porespace watersaturation and also on meteorological conditions. The goal of this study was to estimate the variability of the radon activity concentration in soil gas and to relate it to the variations of soil properties induced by seasonal changes. For this purpose, a long term monitoring of the variation of radon activity concentration in soil gas has been carried out simultaneously to the registration of soil and meteorological parameters at the Jlich Research Center (W-Germany) from February to
December 1997. The recorded time series should be used as a reference for the estimates of seasonal variability for similar locations and help to interpret variations from spot measurements, improving in that way the database for mapping and prediction of the geogenic radon potential.