Ecotoxicological models have been applied increasingly to perform chemical risk assessments since the first models of this kind emerged about 25 years ago. The first ecotoxicological models were applied to very specific cases — for instance, cadmium contamination of Lake Erie or mercury contamination of Mex Bay, Alexandria. The models were inspired by the experience gained in ecological modeling and therefore contained good descriptions of ecological processes. Slightly later, the so-called fate models emerged, which were first developed by McKay and others. Such models described the distribution of a chemical in the atmosphere, the hydrosphere, the lithosphere, and the biosphere.
