DIOXIN, DIOXIN-LIKE PCBS AND ORGANOTIN COMPOUNDS IN THE RIVER ELBE AND THE HAMBURG HARBOR - IDENTIFICATION OF SOURCES

Using neural networks (in this case the Kohonen network) and a multiva riate statistical method - the hierarchical cluster analysis -, a clas sification of dioxin data has been carried out. A principal conclusion , which can be drawn, is that a significant source of dioxin in the ri ver Elbe, Hamburg harbour, the soils of the flood plains of the river Elbe and in soils originating from dredging materials, has been shown to originate from the dioxin contaminated region of Bitterfeld. The re sults indicate that the dioxin contamination in the Bitterfeld region was caused partly by metallurgy processes, not just by chemical produc tion. Furthermore, the results show that a main dioxin source responsi ble for the contamination of Hamburg surface waters, not influenced by the river Elbe, is of ''thermal origin''. The river Elbe shows a char acteristic butyltin pattern. The cause is probably a plant in Bitterfe ld. The precise sources of the dioxin-like PCB are still unknown. (C) 1998 IAWQ. Published by Elsevier Science Ltd.