DISSOLVED AND SUSPENDED FORMS OF CAESIUM-137 IN MARINE AND RIVERINE ENVIRONMENTS OF THE SOUTHERN BALTIC ECOSYSTEM

Danuta Knapińska-Skiba1, Ryszard Bojanowski1, Ryszard Piękoś2

1Institute of Oceanology, Polish Academy of Sciences, 56 Powstancow Warszawy Str., 81-712 Sopot, Poland,
2Medical University of Gdansk, Faculty of Pharmacy, 107 Gen. J. Hallera Av., 80-416 Gdansk, Poland


Dissolved and particulate activities of caesium-137 are presented for the coastal and open southern Baltic Sea waters, fluvial waters (the Vistula and Swina rivers) and lagoon waters (the Vistula Lagoon) during 1996-1999 and compared to those collected before the Chernobyl accident. 137Cs was measured in the Baltic Sea waters at different depths as well as 0.2-0.3 m above the sea bed. In a layer of the Gdansk Bay waters (the Gdansk Deep location), extending from the surface down to 1-2 meters above the sea bed, caesium-137 concentrations ranged between 57 and 66 Bq m-3 in 1999, whereas in the layer situated 0.2-0.3 m above the sea bed its concentration increased up to 87 Bq m-3. This phenomenon was also observed in 1994 and 1998. The concentrations of caesium-137 in riverine suspended particulate matter (r SPM) are lower than in the marine SMP (m SMP) and its activity attains respectively 36 and 222 Bq kg-1 based on dry weight. The proportion of caesium-137 in the suspended form in the Baltic Sea waters does not exceed 2 per cent, while in the fluvial suspended form it is as high as 55 per cent.