Multivariate test designs to assess the influence of zinc and cadmium bioavailability in soils on the toxicity toEnchytraeus albidus

Abstract

AbstractMultivariate test designs were used to identify and quantify the soil parameters important for determining the ecotoxicological effects of zinc and cadmium to the potwormEnchytraeus albidus. The application of a fractional factorial design (FFD) revealed that the acute toxicity of zinc and cadmium toE. albiduscan vary over more than two orders of magnitude, depending on the composition of the (artificial) soils. The differences in metal ecotoxicity were determined mainly by pH and organic matter content or cation exchange capacity (CEC). Using a central composite design, models were developed describing the ecotoxicity of zinc and cadmium toE. albidusas a function of these parameters. To validate the developed surface response models, two field soils and the standard artificial soil prescribed by the Organization for Economic Cooperation and Development (OECD) were spiked with zinc and cadmium, and the acute toxicity toE. albiduswas assessed. These validation experiments confirmed that the toxicity of zinc and cadmium could be predicted by the pH and the CEC of a soil with toxicity decreasing with increasing pH and CEC.