Comparison of soil and sediment ecotoxicity data and test methods : Poster at the 12th SETAC Europe Meeting, Vienna, May 2002

The quality, validity, representiveness and size of data collections of existing ecotoxicity data for chemicals varies to a high extend between the environmental compartments water, sediment and soil. In order to reduce the imbalance of existing data and to be able to proceed with profound and comprehensive risk analyses and evaluation procedures for the environmental compartments soil, water and sediment a successive and comprehensive approach is being developed in this project. The main emphasis is laid on seven organic chemicals and one metal compound (cadmiumchloride) which persist and bioaccumulate. 4,4-DDT, benzo-[a]-pyrene, pentachlorophenol, 2,4-dichlorophenol, trinitrotoluene were selected to cover a relatively wide range of lipophilicity. 3,4-dichloroaniline was selected for its covalent binding characteristics to organic matter. Tributyltin was chosen as an organometallic compound and due to the high acutal environmental relevance. Because of missing soil and sediment toxicity data for these chemicals gaps are being filled experimentally. Sediment toxicity reproduction tests are being conducted using Vallisneria americana, Hyalella azteca, Chironomus riparius, and Lumbriculus variegatus. Three spiked soils are being tested for their toxicity on reproduction of Eisenia fetida, Folsomia candida. Effect parameters for microorganisms within soils are respiration and nitrification. For the plants Avena sativa and Brassica rapa growth and germination are determined. First results in soil toxicity testing for 2,4-dichlorophenol, pentachlorophenol and tributyltin are prestented on this poster. Because of missing aquatoxicity data for the sediment organisms, aquatic toxicity tests (exposition via water) are necessary. First results for 2,4dichlorophenol, pentachlorophenol, cadmiumchloride, 2,4,6-trinitrotoluole and 3,4-dichloroaniline are presented on this poster. Toxicity tests with spiked sediment will follow. Conclusion - obvious soil dependence of the potential NH4-oxidation for all testet contaminants - no soil depending effects on plants and microbial respiration · increases of the EC50-value at a higher clay and silt content for earthworms and springtails - the degree of substance effect on plants and microorganisms is depending on plant species and the kind of microbial activity, respectively - earthworms and springtails show comparable EC50-values - the degree of substance effect is depending on the species - for CdCl2: Hyalella azteca is by factor 100 more sensitive than other tested organisms