Ecological Thresholds For Copper And Nickel In Chinese Agricultural Soils

Theoretical research and computational analysis were carried out based on toxicity data for copper and nickel from Chinese soil. The results provided quantitative evidence to support cross-species extrapolation of copper and nickel toxicity prediction models and obtained the quantitative equations of EC10and EC50for copper and nickel. The species sensitivity distribution (SSD) curves for copper and nickel were fitted with Bur Ⅲ based on toxicity data. Also the toxicity prediction models for copper and nickel were utilized to normalize toxicity data. The5%hazardous concentration for copper and nickel were derived from the SSD curves and the agedHC5, i.e. the ecological thresholds for copper and nickel in soil were obtained by correcting the HC5values with leaching-aging factors. The effects of soil properties on the magnitude of agedHC5values for copper and nickel were studied and the predictive models for agedHC5based on soil properties were developed. The equations for calculating predicted no effect concentration values based on total copper and nickel were established and the recommendation for updating the Chinese current soil environmental quality standards were proposed.