Heavy Metal and Radionuclide Contamination of Sediments from the Skagerrak and Northern Kattegat

Results are summarized from a study over the period April 1988 to April 1989 on the concentrations of 7 heavy metals and of radioactive caesium in sediments at 41 sites in the northern Kattegat and adjacent Skagerrak, where there was accumulation of fine-grained material from the North sea. The highest concentrations of metals and radioactivity were found at sites with a high sediment content of organic carbon, namely in the deeper part of the Skagerrak and the eastern Kattegat. There had been a recent increase in the input of certain metals; possible sources of this are indicated. Caesium activity appeared to have decreased since the early 1980s, but a relatively large proportion of the caesium-137 activity measured at present originated from the Chernobyl accident.