Technetium-99 in Fucus and seawater samples in the Finnish coastal area of the Baltic Sea, 1999

Abstract

Liquid discharges of 99Tc from the Sellafield nuclear facilities increased largely in the mid 90"""s. These releases are transported to the Nordic sea areas by the ocean currents. Results of the 99Tc activities along the Norwegian coastal areas and in the North Sea have been reported but then again, the spreading of 99Tc into Baltic Sea has not been studied thoroughly. Fucus vesiculosus and seawater samples were collected in the summer 1999 from the Finnish coastal areas for measuring 99Tc in the Baltic Sea area. A modified analytical method for measuring 99Tc in the environmental samples was developed at that time. The method based on extraction chromatography and liquid scintillation measurement of 99Tc. The 99Tc concentration in the Fucus vesiculosus in the Finnish coast of the Baltic Sea varied from 1.6 to 11.6 Bq/kg (dry weight) being highest at the most northern sampling sites. These values were considerable lower than those in the Danish and Norwegian coasts. The variation in the concentrations observed are probably due to biological factors. The 99Tc concentration in the Baltic Sea water studied was below 0.2 Bq/m3.