Effects of waste materials on Caenorhabditis elegans (Nematoda) using the ISO standard soil toxicity test

The ecotoxicological characterization of waste according to the European Waste List (HP14) is part of its hazard classification, which is based on 15 different hazardous properties and should include toxicity tests representing the aquatic and terrestrial compartment. Besides established soil toxicity tests with bacteria, plants, and earthworms, the standardized test with the nematode Caenorhabditis elegans (ISO 10872:2010) is suitable for testing soils and wastes, however, has never been validated for the purpose of waste toxicity assessment. Therefore, 23 different waste samples were tested for their toxicity on growth and reproduction of C. elegans to validate the suitability of ISO 10872 (ISO 2010) for assessing the ecotoxicological hazard of waste and to compare the results with those of other ecotoxicological test systems. C. elegans showed a comparable response to the waste samples as the earthworm avoidance test, however, with single samples where the nematodes indicated a higher toxicity than the E. fetida, thus, providing non-redundant information to the ecotoxicological hazard assessment of wastes. Also due to the short duration (4 days) and small-scale test set-up, the soil toxicity test with C. elegans turned out to be a valuable addition to already existing test batteries, for assessing the ecotoxicity of wastes in the soil compartment.