R. Winkler, F. Ruckerbauer, K. Bunzl
Year:
1999
Bibliographic info:
Radon in the Living Environment, 1999, Athens, Greece

From the end of 1996 through March 1999, the spatial and the temporal variability of the soil 222Rnconcentration was investigated at a 20m x 20m test field with porous soil in 0.5 m and 1.0 m depth atnine positions each and at 1m x 1m plots at four positions each. For this, soil gas was collected weeklyinto evacuated scintillation cells and was analysed subsequently for radon activity. In the 20m x 20mfield the spatial variability is characterised by coefficients of variation (C.V.) of 26% at 0.5m, and13% at 1.0 m depth. Within the 1m x 1m plots the C.V. Were 4% and 2%, i.e. Within the uncertainty ofthe method. Time series analysis (TSA) of the soil radon data shows seasonal variations withmaximum concentrations in the winter months. Radon concentrations ranged from 6 to 50 kBq m-3 in0.5 m depth, and from 8 to 34 kBq m-3 in 1.0 m depth. Mostly, the concentrations were higher in 0.5depth than in 1.0 m depth. However, seasonal variation of the 0.5m to 1.0 m concentration ratio hasbeen verified by TSA. To test the variability resulting from different methods, additional proceduresand instruments were investigated at the 20m x 20m field and at a second test field with a different soiltype. Soil gas sampling into evacuated scintillation cells was selected as the reference procedure. Soilradon concentrations obtained with the different sampling procedures and detection methods at the20m x 20m field essentially agreed within the limits of uncertainty of the methods tested. At thesecond test field, i.e. In a largely impermeable soil, deviations up to a factor of two related to thereference procedure were observed.