An approach to assess the regulatory relevance of micro‐evolutionary effects in ecological risk assessment of chemicals: A case‐study with Cd
Courtesy of John Wiley & Sons, Ltd.
We suggest an approach to assess the regulatory relevance of micro‐evolutionary effects of chemicals based on a comparison of concentrations at which micro‐evolutionary effects have been reported in literature and conventionally derived ecotoxicological threshold concentrations. We found reports of micro‐evolutionary effects of cadmium in freshwater organisms at hardness‐normalized concentrations between 0.5 and 6,290 µg Cd · L−1 (normalized to a hardness of 50 mg CaCO3 L−1). These concentrations were at least 1.5 times higher than the hardness‐normalized hazardous concentration for 5% of the organisms (HC5) of 0.34 µg Cd · L−1. This seems to suggest that there is no immediate need to consider micro‐evolutionary effects of Cd in environmental risk assessment of freshwater environments. However, we argue that some other aspects should be kept in mind as well. First, micro‐evolutionary effects have so far only been investigated at few, relatively high concentrations of Cd, and not encompassing the HC5. Second, different types of micro‐evolutionary effects or investigated ecotoxicological endpoints may influence the conclusions of the suggested comparative approach. Finally, factors influencing bio‐availability of Cd were not commonly reported in the literature, which made normalization of concentrations at which evolutionary effects occurred impossible, and which affected the number of studies that could be evaluated in our suggested approach. Environ Toxicol Chem © 2013 SETAC