Strontium-90, cesium-134, and cesium-137 in water reservoirs of Baltic region of the Soviet Union (1986-1988)

Results of strontium-90, cesium-134 and cesium-137 content determination in the water of certain reservoirs in the Leningrad and Kalinin regions, Estonia, Latvia and Lithuania, northern part of Byelorussia, in the period of 1986-1988 are presented. It is shown that in the regions examined cesium-134 and cesium-137 are the main dose-forming nuclides, which were transferred by air flows from the Chernobyl NPP region as a result of the accident. It is ascertained that contamination of the rivers and lakes in the western part of the Baltic region is less significant than in the eastern part, owing to irregular atmospheric radioactive atmospheric radioactive falouts in 1986. A rapid decrease in the level of the river and lake water pollution is pointed out. Cesium-137 effluents with waters of some large Baltic rivers is the USSR territory to the Baltic Sea in 1986-1988 are evaluated