PARENT SESSION

2D - Mechanisms of toxic action
Poster Hall
8:30 AM - Monday, 28 April 2003
Chair: Dietrich, D.¹, ¹
Co-chair: Haux, C.², ²

(MOP/95) Ecotoxicological risk assessment of surface waters: a modular approach integrating in vitro methods.

Schweigert, Nina¹, Behra, Renata¹, Escher, Beate¹, Burkhardt-Holm, Patricia¹, Eggen, Rik¹, ¹ EAWAG (Swiss Federal Institute for Environmental Science and Technology), Dübendorf, Switzerland

ABSTRACT- In Switzerland a modular concept has been developed in order to evaluate the quality of Swiss streams. In this integrated assessment, hydrological, morphological, biological, chemical and ecotoxicological aspects are brought together. In the module ecotoxicology sensitive test systems are necessary as the concentrations of pollutants in surface waters in Switzerland, as well as in many other countries, are mostly low. The suggested tests shall later be routinely used by environmental agencies for the screening of large numbers of water samples for the ecosystems health. So the main criteria for the test systems are cost-efficiency, short duration and an easy handling. Further requirements, which shall be met, were: high sensitivity, high reproducibility, their relevance for the ecosystem, the possibility to be automated and a reduced use of experimental animals. Furthermore the tests shall cover different toxic responses. A pragmatic solution fulfilling most of these requirements was developed, consisting of a two-tiered approach. At the moment, the main focus is put on the first tier, consisting of a test-battery covering the following toxic responses: direct toxicitiy (narcosis), DNA-damage, endocrine disruption, inhibition of photosynthesis, teratogenicity. In vitro methods have been chosen for this screening step. The test-systems are exchangeable and the test-battery can be adapted to further developments. An integration of test-systems responding to immunotoxicity and neurotoxicity is later also possible, when adequate test-systems have been developed. Here the general concept and the first results will be presented.

Key words: screening, test-battery, environmental samples