Registration Dossier

Diss Factsheets

Ecotoxicological information

Sediment toxicity

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

Lumbriculus variegatus: EC10 = 15.3 mg/kg d.w. (survival, measured concentration)

Key value for chemical safety assessment

Additional information

Two prolonged sediment toxicity test using spiked sediment have been carried out with the midge Chironomus riparius (Egeler et al., 2002) and the worm Lumbriculus riparius (Egeler and Nesa 2002). The test protocol was based on the OECD draft test Guideline 218 with some deviations. The sediment used in the test was an artificial sediment consisting of 5% peat, 20% kaolinite clay and 75% quartz sand. The sediment had a mean organic matter content of 2 ± 0.5%. As food source for the test organisms urtica powder in a concentration of 0.5% of sediment dry weight was added. The test substance was added to the sediment as an aqueous solution. The test system was allowed to equilibrate for 48 hours before the animals larvae were introduced.

Mean recovery rates of test substance concentrations were 30 and 37.2 % for the Chironomus test and Lumbriculus test, respectively. Nominal concentrations were corrected accordingly.

The following endpoints were determined:

Chironomus riparius: NOEC = 37.5 mg/kg d.w. (emergence, measured concentration)

Chironomus riparius: NOEC = 75 mg/kg d.w. (development rate, measured concentration)

Lumbriculus variegatus: NOEC < 11.6 mg/kg d.w. (reproduction and growth, measured concentration)*

Lumbriculus variegatus: EC10 = 15.3 mg/kg d.w. (survival, measured concentration)*

*The results of the study with Lumbriculus variegatus show a clear dose-response relationship for the endpoint survival. However, for the endpoints biomass and reproduction there were clear effects from the lowest concentration level on. Therefore, no dose-response relationship could be calculated for these endpoints.

 

Derivation of PNECsediment

From both tests it can be concluded that Lumbriculus is more sensitive to aniline in sediment than Chironomus. Although no NOEC could be determined for the sublethal endpoints, the EC10 determined for the endpoint survival (15.3 mg/kg dw) is about a factor of 2 lower than the EC10 from the Chironomus study for the endpoint emergence.

 

Therefore the EC10 for survival of Lumbriculus was used as basic value for the derivation of PNECsediment. In consideration, that the sublethal endpoints reproduction and growth are more sensitive, an assessment factor of 100 could be applied to the EC10 of 15.3 mg/kg dw resulting in a PNECsediment of 153 μg/kg dw.