Lemna Growth Inhibition Test

Abstract

The Lemna growth inhibition test was part of the additional aquatic test battery within the ring test. The number of reported data sets was sufficient for statistical assessment. The methodology and the results show that the Lemna (Duckweed) test, using a higher plant as test organism, can be successfully applied to assess waste eluates. The results for the different substrates are within the same range as the other biological test systems, with only weak effects in SOI eluates, medium ecotoxicity for INC and the detection of a clear ecotoxic response for WOO eluates. The phytotoxicity of waste eluates cannot be covered only by the Algae test and the use of unicellular organisms. By using the higher plant Lemna, the test results enable a better understanding of the impact of waste material on macrophytes in the ecosystem. More information on the environmental risk assessment of waste to be reused in the environment makes the Lemna test valuable for an enlarged biotest battery. For samples with specific limitations to application of biotests, such as colour, turbidity, high Ammonia content or a non-neutral pH value, the Lemna test can be recommended even for a limited test set, such as waste classification.