LAUSR

The activity concentrations of terrestrial and fallout radionuclides are investigated in soil and sediments from highway stormwater retention ponds. The increased activity of 40K, 238U and 232Th in sediment respect to soil samples (approximately 20% higher) is found to be correlated with the erosion of clay minerals. Therefore, it can be a useful fingerprint to assess the highway bank stability in long-term measurements. Fallout radionuclides, especially 7Be gives a clear indication of the well operation of the drainage system and the retention ponds, with activity concentrations in sediment samples up to 131.4 ± 7.8 Bq kg−1. Finally, these results are used to assess the potential external exposure to gamma radiation of the general population and worker due to maintenance operations.