The aim of the investigations was to determine activity concentration of radioactive isotopes in soil samples collected from different provinces of Hungary.Earlier studies have proved that the 222 Rn activity concentration is higher than permitted in some wine cellars. To investigate the reason for this phenomenon, the activity concentration of soil samples was measured.Analyzing 137 Cs isotope activity in samples collected from the area of a watercourse it was possible to determine the silting-up rate.Activity concentrations were measured for red mud originating from an industrial disaster.