Pu-239+240 and Cs-137 in Montenegro soil: their correlation and origin

The 239+240Pu activity concentrations in soil from Montenegro (six samples from three localities) have been measured for the first time. The alpha and gamma-spectrometric measurements are used to determine the 239+240Pu/137Cs activity ratio, and it was found to be with an average of 0.02 and standard deviation of 0.007. This average activity ratio was applied to estimate 239+240Pu in soil samples from the other 21 localities at which 137Cs activity concentrations were measured. In this research obtained (either experimentally or estimated) 239+240Pu activity concentrations (0.036–8.265 Bq kg−1) are comparable with those measured in some other European countries. On the basis of the results obtained in the present study and a survey of relevant literature, it is possible to conclude that Chernobyl contribution to 137Cs contamination of Montenegro soils is dominant, whilst Pu contamination comes from the global fallout of nuclear weapon tests.

► Pu-239 + 240 and Cs-137 in Montenegro soil. ► Activity concentrations decrease with soil depth. ► Cs is dominantly deposited from the Chernobyl accident. ► Pu is deposited from atmospheric nuclear tests.