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No. 146: Assessment of hazardous substances in Danish sediment and biota according to Norwegian, Swedish and Dutch quality standards

Jensen, J., Sanderson, H., Larsen, M.M., Johansson, L.S. & Kallestrup, H. 2019. Assessment of hazardous substances in Danish sediment and biota according to Norwegian, Swedish and Dutch quality standards. Aarhus University, DCE – Danish Centre for Environment and Energy, 38 pp. Technical Report No. 146 http://dce2.au.dk/pub/TR146.pdf

Summary

This report compares monitoring data in sediment and biota for 14 hazardous substances found in Denmark with quality standards (EQS) used in Sweden, Norway and the Netherlands. Firstly, the Swedish, Norwegian and Dutch EQSs were assessed according to transparency in derivation and usability in assessment of the status in Danish surface water bodies. When comparing with the identified usable EQS  the concentrations found in Danish biota samples are with the exemption of TBT, generally below the used EQS values, whereas sediment samples frequently are found in concentrations that exceed the EQS for metals, especially zinc, nickel and arsenic. However, the comparisons for metals are without considering natural background concentrations, as these have not been stablished for Danish sediments.  Firm conclusions regarding the status of the observed concentrations of metals in Danish sediment samples therefore await the identification of such background concentrations.