Distribution coefficients and concentration factors of ~(226)Ra and ~(228)Th in the Greek marine environment

摘要

The levels of ~(226)Ra and ~(228)Th in sea water, sediment and biota were measured in some selected areas in the sublittolar zone of Ikaria Island, Loutraki in continental Greece and Milos Island. The concentrations of ~(226)Ra and ~(228)Th were found to be significantly elevated in sea-water, sediments and biota in Ikaria Island. The results obtained were used for the evaluation of distribution coefficients and concentration factors by applying a linear and a non-linear regression analysis. The high distribution coefficients estimated for ~(226)Ra and ~(228)Th indicate that a large proportion of each radionuclide considered remains in the solid phase. In general, the estimated values of the concentration factors of ~(226)Ra and ~(228)Th in Algae and P. oceanica seem to follow the linear model of analysis in Ikaria and Loutraki, where the concentrations in sea water were high. The respective concentration factors from Milos were found to satisfy the non-linear model of analysis. Concentration factors in certain fish species were found to satisfy the non-linear model of analysis for the three areas studied.