Cadmium toxicity for terrestrial invertebrates: Taking soil parameters affecting bioavailability into account

Acute and chronic ecotoxicity tests with cadmium were conducted with the ea rthworm Eisenia fetida, the potworm Enchytraeus albidus and the springtail Folsomia candida. To assess the influence of the soil type on cadmium bioav ailability, these tests were carried out in a standard artificial soil, in a sandy and a loamy field soil. It was not possible to evaluate the influen ce of soil parameters on the bioavailability on the basis of the experiment s that were conducted in only three different soil types, therefore, litera ture data were also included. However, even in the same standard artificial soils, toxicity data in the literature for Eisenia fetida and Folsomia can dida varied considerably. Consequently, no models could be developed that a llow a normalization of the ecotoxicity of cadmium to parameters controllin g bioavailability. In contrast to zinc, effect concentrations of cadmium fo r terrestrial invertebrates were always much higher than background concent rations. As the effect of aging on the bioavailability of cadmium was never taken into account, because toxicity experiments were always carried out i n freshly spiked soils, these effect concentrations may even be regarded as conservative. Furthermore, the zinc-cadmium ratio in soils is usually so h igh that the risk of zinc ecotoxicity for terrestrial invertebrates will us ually be much greater in comparison to cadmium ecotoxicity.