PARENT SESSION

2K - Sediment Assays
Poster Hall
8:30 AM - Tuesday, 29 April 2003

(TUP/145) Ring tests for sediment toxicity and bioaccumulation with aquatic oligochaetes.

Egeler, Philipp¹, Junker, Thomas¹, Roembke, Joerg¹, Knacker, Thomas¹, ¹ ECT Oekotoxikologie GmbH, Floersheim/Main, Hessen, Germany

ABSTRACT- During the current revision of the Technical Guidance Document (TGD) for risk assessment of new and existing chemicals within the European Union, the sediment is receiving increasing attention. Therefore, standardised techniques for assessing the risks of exposure to sediment-associated chemicals are required. The use of endobenthic organisms (e.g. aquatic oligochaetes) ensures that all exposure routes including pore-water and sediment-ingestion are taken into account. Two new test methods have been established and are about to be ring-tested. The ring tests have been commissioned by the German Federal Environmental Agency (UBA), Berlin, and will be organised by ECT Oekotoxikologie GmbH, Floersheim, Germany. Based on U.S. standard methods, a standardisable test method was developed using the aquatic oligochaete Lumbriculus variegatus (Müller), measuring lethal and sublethal endpoints (survival, reproduction and biomass) in spiked artificial sediment. After validation of the test method in an international ring-test, it is intended to submit a draft guideline to OECDs Test Guideline Programme. Existing national guidelines covering bioaccumulation of sediment-associated chemicals (e.g., ASTM, U.S. EPA) mainly address the testing of contaminated field sediments in order to assess sediment quality. A standardised sediment bioaccumulation test method for testing single compounds is lacking. In order to study bioaccumulation of sediment-associated chemicals, an intimate contact of the test organisms with the sediment phase is desirable. Therefore it is recommended to use aquatic oligochaetes, e.g. Tubifex tubifex (Müller), Lumbriculus variegatus or the tropical tubificid Branchiura sowerbyi (Beddard), as representatives of endobenthic fauna. Taking into account existing guidelines, a draft guideline according to OECD format was formulated. The method described in this draft guideline will be evaluated in an international ring test. The presentation will give an overview of the methods to be validated and will outline the ring test projects.

Key words: bioaccumulation, Sediment toxicity, endobenthic organisms, oligochaetes