Bioassay-directed identification of organic toxicants in river sediment in the industrial region of Bitterfeld (Germany) -: A contribution to hazard assessment

Bioassay-directed identification of toxicants in an acetonic extract of a sediment of the riverine Spittelwasser in the industrial region of Bitterfeld (Germany) was conducted. For this purpose, a combination of chromatographical fractionation, chemical analysis, and a biotest battery including Vibrio fischeri ((inhibition of bioluminescence), Daphnia magna (immobilization), and Scenedesmus vacuolahks (inhibition of cell multiplication) was applied. Major toxicants identified and confirmed were methyl parathion (D. magna), prometryn, N-phenyl-beta-naphthalene amine, PAHs (S. vacuolatus), and tributyltin tall biotests). Toxicity to V; fischeri; was dominated by elemental sulfur. Results indicate high toxicant loads in the sediment about 7 years after closedown of a majority of chemical production sites at Bitterfeld. Comparison of potential exposure and toxicity data indicate a severe hazard potential to aquatic organisms due to organic toxicants. The results illustrate the potency of a biotest battery for identification of toxicants in contaminated sediment within the frame of toxicity identification procedures.