Sediment-Water Chironomid Toxicity Test Using Spiked Sediment (OECD TG 218)
The Sediment-Water Chironomid Toxicity Test using spiked sediment according to OECD TG 218 is designed to assess the effects of substances on sediment-dwelling aquatic invertebrates. The test focuses on Chironomus species (non-biting midges), which are ecologically relevant organisms inhabiting freshwater sediments and play an important role in benthic food webs.
In this study, the test substance is incorporated directly into the sediment, creating a defined exposure scenario for the organisms. Larvae of Chironomus are then introduced and exposed under controlled laboratory conditions, typically over a period of 28 days.
Key endpoints include larval survival, growth (e.g. dry weight), and emergence of adults. These parameters allow the establishment of concentration–response relationships and the determination of chronic toxicity endpoints such as the No Observed Effect Concentration (NOEC) and the Lowest Observed Effect Concentration (LOEC).
This test provides essential information on the potential impact of chemicals on benthic organisms and sediment quality, contributing to a comprehensive environmental risk assessment of substances in aquatic ecosystems.
