Sensitivity of Ostracods to U, Cd and Cu: The Case of Cypridopsis vidua

Abstract

The development of uranium mines has been necessary to obtain abundant and scarce uranium resources, but they also bring inevitable radioactive contamination to the surrounding soil, rivers and lakes. This paper explores the sensitivity of Cypridopsis vidua to the radioactive element uranium and the heavy elements cadmium and copper with single and combined acute toxicity experiments and combined toxicity model predictions. The results from the single toxicity experiments showed that the degree of toxic effects was cadmium > copper > uranium. The combined toxicity experiments showed that the compound toxicity of U-Cd and U-Cu was higher than the weakest component and lower than the strongest component, whereas the compound toxicity of Cd-Cu was higher than either of its components. When the overall proportion of a more toxic metal was increased, its mixed toxicity also increased, and vice versa. Combined toxicity predictions showed that the U-Cd combination was best described by the concentration additive (CA) model, the independent action (IA) model was more applicable to the Cd-Cu combination, and the most applicable model for the U-Cu combination changed depending on the concentration gradient. The acute toxicity data from this study provide a reference for the development of wastewater discharge standards for uranium mines, enriches the data related to the toxicity of uranium for ostracods and deepens the understanding of the threat of uranium pollution to aquatic ecosystems.

Identification of the single and combined acute toxicity of Cr and Ni with Heterocypris sp. and the quantitative structure-activity relationship (QSAR) model

“…Three sigmoidal nonlinear functions ( Table 3 ) were selected for fitting based on the concentration-response data of this experiment, and the best fit was selected. The quality of the model was evaluated using the coefficient of determination (R 2 ), root mean square error (MSE), or mean absolute error (MAE) [ 49 ].…”

“…In the CRC fitting process, an additional observation confidence interval (OCI) was incorporated. This OCI accounts for both the uncertainty of the raw observation data and the uncertainty associated with fitting the nonlinear function to the experimental data [ 49 ].…”