Interim report of the HELCOM CORESET project

108
Temporal trends in concentrations of the artifi cial radionuclide caesium-137 in
plaice and fl ounder muscle as well as sea water in the Baltic Sea basins
Key message
Overall, the Cs-137 activity concentrations in plaice and fl ounder muscle, as well as of surface waters, in
the Baltic Sea basins are approaching pre-Chernobyl levels.
Cs-137 is continuously transported from the Baltic Sea to the North Sea via Kattegat. Routine discharges
of radioactivity from nuclear power plants into the Baltic Sea area are small and only detectable
locally.
137
Cs concentration above target value
137
Cs concentration below target value
Target level = 2.9 Bq/kg
© National Land Survey, Finland, 81/MYY/07
Finnish Environment Institute
SYKE, FINLAND 2011
Data source: Helsinki Commission (HELCOM)
Figure 3.6. 137Cs concentrations (in Bq/kg) in plaice and fl ounder muscle in 1984-2009, as annual mean
values by basin. GES boundary values have been calculated as average of pre-Chernobyl (1984-1985) concentrations.