RADON MEASUREMENTS IN SOIL TO PREDICT INDOOR RADON CONCENTRATIONS IN NEW BUILDINGS IN AN AREA WITH UNUSUALLY HIGH RADON LEVELS

We investigated the possible correlation between measurements of radon concentrations in soil and indoor radon concentrations. Such a correl ation could be used to estimate the radon concentrations to be expecte d in new buildings, which is important for the evaluation of building plots. For this purpose, we measured the seasonal course of radon conc entrations in 41 tubes along two profiles in an area with unusually hi gh radon levels (Umhausen, 2600 inhabitants, Tyrol, Austria). Parallel to the measurements in the tubes, radon concentrations were measured in the basements of 30 houses located within a radius of 15 m around t he tubes in July 1992 and in February 1993. Linear correlation analysi s was performed to establish the correlation between the indoor measur ements and the measurements in the tubes. Measurements of radon concen trations in soil give only limited information about the radon concent rations to be expected in new buildings, and seasonal and local variat ions make predictions based on spot measurements unreliable.