Use of bioassays for assessment of water-extractable ecotoxic potential ofsoils

The characterization of contaminated soils is based on heterogeneous strate gies considering chemical analyses or bioassays, In the report Bioassays fo r soils, test methods which are at an advanced state of development and sta ndardization are recommended by the German DECHEMA (German Society for Chem ical Apparatus, Chemical Engineering and Biotechnology e.V.). Following thi s report six soil samples contaminated with different organic and inorganic substances are applied to bioassays using the following organisms: Scenede smus subspicatus, Daphnia magna, Vibrio fischeri, Pseudomonas putida. Addit ionally, they are chemically analyzed. The test results demonstrate that to xic contaminants are present and bioavailable in water elutriates from two soils, indicating the necessity of bioassays and chemical analyses to predi ct potential risks from contaminated soils. Furthermore it is demonstrated that the described qualitative approach for the assessment of test results is not sufficient to quantify the risk potential of contaminated soils. (C) 2000 Academic Press.