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(13-04) Suitability of duckweed (Lemna minor) for biotesting of soil . Eberius, Matthias*,1, Altenburger, Rolf2, Reiners, Svea2, Kalsch, Wolfgang3, Meller, Michael3, Römbke, Jörg3, Reuter, Ilka4, Mennicken, Guido4, Schuphan, Ingolf4, 1 LemnaTec GmbH, Würselen, Germany2 Umweltforschungszentrum Leipzig Halle GmbH, Leipzig, Germany3 ECT Oekotoxikologie GmbH, Flörsheim am Main, Germany4 RWTH Aachen, Aachen ABSTRACT- Higher plants are dramatically under-represented in ecotoxicological risk assessment. Therefore the duckweed growth inhibition test as it is currently standardised in ISO CD 20079 was evaluated by three laboratories for soil elutriates in the frame of a larger joint research project on risk assessment of contaminated soils with biotest batteries (Fraunhofer IUCT, DBU). Lemna minor can be demonstrated to be one of the most sensitive aquatic organisms towards a wide range of different xenobiotics from heavy metals to organics like explosives, PAH, mineral oil products even at low environmentally relevant concentrations. Elutriates of non-contaminated soils and soils with low background levels for common contaminants were clearly non toxic. Thus the duckweed test has a high potential to detect toxic elutriates of contaminated sites in screening and final tests but is robust against a wide range of matrix effects. In close connection to the practical work intensive studies were made to maximize reproducibility and to use appropriate calculation methods for growth inhibition. In many cases frond area as observation parameter measured by image analysis was more sensitive than frond number showing the value of using this new technology in ecotoxicity testing. The ISO test design was shown to give highly reproducible and sensitive results. Therefore the duckweed test is able to fill the gap of higher plants in many biotest batteries working with soil elutriates. Key words: Soil, ecotoxicity testing, duckweed, elutriate |
