Radionuclide contamination of the Bay of Varna for the period 1986 - 1992

Atmospheric fallouts from the radioactive cloud passed over the Black sea in the first days of May 1986 were a source of contamination of the Bay of Varna with artificial radionuclides. This conclusion is confirmed by the following facts: increased total beta radioactivity of the see water (up to 15 Bk/l) and higher average values till 1990; higher values of cesium-134 and cesium-137 in sea water and fishes compared to controls (samples measured before May 1986); cesium-134/cesium 137 ratio 1:10 in sea water, fishes, bottom sediments, seaweed. 2 tabs. (A.B.)