On variations of volumetric activity of 90Sr and 137Cs in the Baltic Sea coastal waters near the shore of Lithuania in 2005–2009

The article presents the measurement results of the volumetric activity (VA) of artificial radionuclides 90Sr and 137Cs in the coastal waters of the Baltic Sea near the Curonian Peninsula in 2005–2009. The annual average values for this period of time were 12 Bq/m3 (90Sr) and 40 Bq/m3 (137Cs). Considerable variations in the VA of the radionuclide in individual measurements compared to the average results were observed. The extreme values were 6 and 16 Bq/m3 for 90Sr and for 137Cs—27 and 75 Bq/m3. It is proposed to allow such variations under the influence of a variety of external factors such as hydro meteorological situations, inflowing rivers and bays, storm activity and etc. Besides, a possibility of penetration of radionuclides into the sea waters from the additional radioactive sources is not excluded.