Avoidance test with Eisenia fetida as indicator for the habitat function of soils
Results of a laboratory comparison test
Intention, Goal, Scope, Background. The habitat function of soils is often assessed using the reproduction test with Eisenia fetida. As this test is rather labour-intensive, an alternative is needed which is less cost-intensive in terms of duration and workload, but gives reasonable results. The avoidance test with E. fetida is a suitable screening test meeting these criteria. However, before a novel test system can be generally recommended it has to be ensured that comparable results are acquired from different laboratories on the basis of the respective test guideline. Objective. The avoidance test with E. fetida was performed as laboratory comparison test. The results were compared with those of the earthworm acute and reproduction test carried out with the same soils. Methods. The three tests were performed by three laboratories using eight contaminated soils and three control soils. The contaminated soils were mixed with the control soils to obtain different concentrations of the contamination. Results and Discussion. The results of the avoidance test show that despite the partially considerable standard deviations a 72% agreement in the assessment of soils was reached with a toxicity criterion of >80% avoidance response. The sensitivity is at least that for the reproduction test and considerably surmounts the sensitivity of the acute test. Recommendation and Outlook. The avoidance test is considered to be a suitable screening test for assessing the habitat function of soils. The whole test design could be improved by reducing the standard deviations among parallel test batches. With regard to standardization it is recommended to use control soils which have the same properties as the soils described in respective guidelines. (e.g. ISO 11269-2, OECD 216, 217).