Can Ecological Models accurately predict mixture toxicity at the population level or is clairvoyance still needed?
Spotlight on ARCHE Consulting’s Research
Contrary to standard laboratory tests, the ecological reality of exposure in the field is much more complex. For example, the presence of multiple chemicals and interactions with various organisms increase the uncertainty of current risk assessment methods. Population models bridge the gap between the lab and the reality in the field. Our research applied population models to long-term experimental data on the combined effects of four chemicals (pyrene, dicofol, alfa-hexachlorocyclohexane, and endosulfan) on water flea (Daphnia magna) populations.
Using only standard toxicity data of the single compounds, the model could predict how different combinations of these chemicals affect Daphnia populations, both after constant exposure and a short-term pulse. Comparison with traditional statistical analysis of the population data showed that the population model performs at least as good as the statistical approach. Considering that the modelling approach only requires chronic toxicity data on the individual chemicals, this novel technique offers clear advantages over the statistical approach. The use of population modelling can be pivotal to gear up toward a novel and realistic approach for the ecological risk assessment of mixture exposure scenarios.