Radionuclide distribution in the Barra de Valizas—Aguas Dulces Region, Uruguay

The 238 U, 226 Ra, 210 Pb, 232 Th, 40 K, and 137 Cs activity concentrations in sand, soil, sediments, and Baccharis trimera were determined by gamma spectrometry. Gross alpha—beta activity and 226 Ra, 228 Ra, and 210 Pb activity concentrations in water were also evaluated. The radionuclide mobility between compartments was assessed, and the transfer factor between soil and vegetation was calculated. In general, 238 U series were not in secular equilibrium with 226 Ra loss and 210 Pb enrichment. The 226 Ra, 228 Ra, and 210 Pb activity concentrations in water were below the detection limit in all analyzed samples. The 210 Pb, 40 K, and 137 Cs activity concentrations in Baccharis trimera and the transfer factor from soil were quantified in different seasons. The 210 Pb transfer factor ranged from 0.41 to 2.33, as affected by precipitation. Finally, 137 Cs could only be identified in samples collected in winter. This work provides a radiological condition baseline of the region of Barra de Valizas—Aguas Dulces, and it will be useful for assessing future effects due to human impact.