Comparative analysis of 239Pu, 137Cs, 210Pb and 40K spatial distributions in the top soil layer at the Baltic coast

This paper presents the results of an investigation into the spatial distribution of radionuclides of artificial (Pu-239.240, Cs-137) and natural (Pb-210, K-40) origins in the upper (0-5 cm) soil layers on the Baltic coastline of Lithuania (similar to 5 km(2) area). The samples were analysed by gamma ray spectrometry and combined radiochemical procedures. The highest Pb-210, Pu-239.240 and Cs-137 activity concentrations were determined in the forest samples, whereas K-40 activity was rather homogeneous across the study area. Relatively high Pu-239.240 and 40K activity concentrations were determined along the surf zone. The Pb-210 and Cs-117 activity concentrations showed a gradual increase from the surf zone to the forest. The average activity concentrations of Pu-239.240, (CS)-C-137, Pb-210 and K-40 in the beach and forest samples, respectively, were as follows: 0.32 +/- 0.08 and 0.74 +/- 0.14; 50 +/- 4 and 1190 +/- 50: 4.7 +/- 2,0 and 48 +/- 6; 186 +/- 15 and 216 +/- 17 Bq/kg. (c) 2005 Elsevier Ltd. All rights reserved.