The basic patterns of the distribution, migration and accumulation of radionuclides in the bottom sediment of the Baltic Sea

Abstract

This paper focuses on the impact of certain factors on the contemporary distribution of natural (226Ra, 232Th, 40К) and anthropogenic (137Cs, 60Co) Key words: radionuclide distribution patterns, Baltic Sea, hydromica, pH barrier, sediment fractions, grain-size composition.A number of researchers have studied the features of migration and accumulation of natural and anthropogenic radionuclides. In particular, one of the fundamental works is Artificial radionuclides in marine environment by V. V. Gromov and V. I. Spitsin [6] dedicated to the problems of migration and sorption of anthropogenic radionuclides in oceans. A significant contribution to the study of this issue has been made by I. Ye. Starik, A. P. Lisitsyn, N. M. Strakhov, G. G. Matishev and D. G. Matishev, V. P. Tishkov, V. V. Anisimov, and many others. However, these researchers have focused mainly on radionuclide distribution and behaviour in oceans, at significant depths, in certain sedimentation conditions, and in the presence of long-lasting processes of radionuclide migration in the aquatic environment. The conditions of migration and accumulation of main gamma-emitting radionuclides in the bottom sediment in a relatively shallow basin of the Baltic Sea with dramatic changes in the bathymetric level, the composition of bottom sediment, redox and acidbase characteristics and a significant amount of substances coming from the shore have specific features and are of special interest. Another important aspect of the issue is the immediate influence of the "Chernobyl trace" on the water area of the Baltic Sea.