PARENT SESSION

Interactive Poster Session: Soil Ecotoxicology
Hall 18
8:35 AM - 12:30 PM, Tuesday, 29 April 2003
Chair: Römbke, J.¹, ¹
Co-chair: Eisenträger, A.², ²

(TU18/5) Soil columns (MS-3) for ecotoxicological characterization of contaminated soils.

Fernández, Maria Dolores¹, Vega, María Milagrosa ¹, Babin, Mar¹, Pro, Javier¹, García, Pilar¹, Tarazona, José Vicente¹, ¹ Laboratory for Ecotoxicology. Dpt. of Environment. INIA. MCYT, Madrid, Spain

ABSTRACT- MultiSpecies Soil System (MS-3) is a microcosms system designed for assessing of substance toxicity on soil dwelling organisms, developed in the Laboratory for Ecotoxicology. MS-3 method consists on soil columns where substance toxicity is determined for soil organisms covering three taxonomic groups (earthworm, plants and microorganisms). Furthermore, toxicity for aquatic organisms (algae, daphnia and fish cell) is determined in column leachates. Advantages of this column method are: simultaneous determination of soil-water transfer and toxicity to soil and aquatic organisms, and assessment of interaction among the different taxonomic groups. This method was evaluated for their application in the assessment of polluted sites. With this aim, soil samples taken from sites contaminated with organic and inorganic substances were tested. The method, previously developed for pure chemicals was adapted to allow the evaluation of these complex samples. Thus, successive dilutions of tested soil with a control soil (high sand content and low organic matter content) were performed. Mixtures were introduced in methacrylate tubes in previously determined conditions. Toxicity to soil organisms was assessed in the soil columns in a 21-days test accomplished following OCDE method adapted to soil mixtures. Soil columns were watered daily and toxicity of total collected leachates was assayed on aquatic organisms at the end of the test. L(E)C50 values for the different organisms were determined from the dose-response curve. In addition, criteria based in direct toxicity assays were established, in order to declare a soil as polluted, non polluted or potentially polluted. Comparison of end-point values obtained in toxicological assays to established criteria allowed the ecotoxicological classification of soils.

Key words: Soil column, MultiSpecies Soil System, Ecotoxicological characterization, Contaminated soils