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(33-03) Dynamic models for metal accumulation under ecologically realistic exposure scenarios. Blust, Ronny*,1, Steen Redeker, Erik1, Van Campenhout, Karen1, Bervoets, Lieven1, 1 Department of Biology, Antwerp, Belgium, Belgium ABSTRACT- Water quality criteria for metals have been derived from acute and chronic exposure experiments with different types of organisms. A general assumption made is that the metals present in the solution are the main source of exposure and responsible for the toxic effects. This approach largely neglects the role of dietary and other exposure sources in metal uptake and toxicity. Nonetheless, it has been shown that dietary or sedimentary exposure may contribute significantly to metal accumulation and chronic metal toxicity. However, it is not yet clear to what extent these different sources actually contribute to metal accumulation and toxicity under ecologically realistic exposure conditions. This requires the combination of experimental studies with field monitoring and dynamic modeling of the processes. The results of such studies have been used to model the accumulation of metals and predict metal tissue concentrations in freshwater invertebrates and fish under a variety of exposure scenarios. The results of these simulations are compared with the results of field monitoring campaigns in which metal concentrations have been measured in different exposure compartments and organisms. Furthermore, it has been evaluated to what extent the measured or estimated metal body concentrations can be used to predict metal toxicity. The results show that metal body concentrations only explains part of the observed toxicity and that factors such as the exposure routes, metal uptake and turnover rates and exposure time are important factors that have to be taken into consideration when relating metal exposure to metal toxicity. Key words: metals, accumulation, toxicity, modelling |
