Individual and combined effects of zinc, cadmium and copper on the marine amphipod Allorchestes compressa

Abstract

The acute toxicity of zinc, cadmium and copper to A. compressa was assessed in single, paired and triad combinations. Copper was 1.6 times more toxic than cadmium and 4 times more toxic than zinc. When tested in combinations of paired metals, independent dissimilar and simple similar action models, both of which are non-interactive in their classification, were rejected. In one case, the expected mortalities were lower (antagonism) which suggested that paired metals acted interactively. For the combination of three metals, the mortalities were predictable by the simple similar action model (non- interactive). Except for the Zn-Cd combination, the toxic unit concept underestimated the expected mortalities in the test combinations.