The Elbe Flood in August 2002—Organic Contaminants in Sediment Samples Taken After the Flood Event

Abstract

In the course of this study 37 sediment samples were analyzed. They were taken after the flooding in September 2002 along the Elbe and at the mouths of its major tributaries. The sampling program covered the entire river stretch that was affected by the floods, from Obristvi (Czech Republic) to the Elbe estuary (North Sea) on the German coast. Analyses were performed for dioxins, nonylphenols, nonylphenol ethoxylates, bisphenol A, DEHP, musk fragrances, polybrominated diphenylethers, chloroalkylphosphates, organochlorine compounds, PAH, and organotin compounds. The results show that only a few weeks after the flood, contaminant concentrations in solid matter were comparable to those prevailing beforehand. Significant sources of contaminant input proved to be the tributaries Vltava (Moldau), Bilina (both in the Czech Republic), and the Mulde (Germany), as well as industrial and municipal sewage treatment works (STW) located along the Elbe. Further point sources are to be found in still water zones such as harbors and abandoned channels. These sources are activated when erosive action stirs up older sediments. Statistical analyses of the congener distribution of the dioxins provided evidence on the sources of these contaminants and freight levels in different river sections. The chemical analyses were complemented by results of ecotoxicological investigations with two sediment organisms (Chironomus riparius and Potamopyrgus antipodarum).

Keywords:

• Elbe flood
• Sediments
• Dioxins
• Xenoestrogenic plasticizers and detergents
• Musk fragrances
• PBDE
• Chloralkylphosphates
• Organochlorine compounds
• PAH
• Organotin compounds
• Ecotoxicological investigations

ACKNOWLEDGMENTS

We thank our colleagues Jiri Medek from Povodi Labe and Jan Valek from Povodi Vltavy for their excellent support during the sampling and Ute Ehrhorn from the Elbe Water Quality Monitoring Agency for producing the illustrations. The determination of concentration levels for polybrominated flame retardants was funded in part by the German Ministry of Education and Research. We gratefully acknowledge Anja Herz's valuable technical assistance with sample analysis.

Notes

*This paper was presented in the third workshop organized by SedNet working group on “Monitoring Sediment Quality at River Basin Scale” held at IPIMAR, Lisbon, Portugal, January 29–31, 2004.