Including different biological and space complexity scales in hazard assessment : a case study with diclofenac sodium PNEC derivation
Résumé
Use of parent and metabolized drugs and their subsequent indirect emissions in aquatic ecosystems are a source of contamination of these and implies improvement of the scientific knowledge on their likely ecotoxicological impacts and of the tools to assess them. This is the goal of the DOREMIPHARM project, which aims at providing robust ecotoxicological data for drugs judged as of concern for their potential ecotoxicological risk as regards aquatic ecosystems. More widely, this research project also aims at developing robust hazard assessment tools for these pharmaceutical substances. The project involves different partners and their corresponding skills in order to implement a large number of tools allowing the testing of different conventional and non conventional endpoints (from a regulatory viewpoint). The project tasks allow data production for the implementation of an environmental risk assessment of the pharmaceuticals. The aim of this poster is to give an overview of the possible levels of assessment that may be taken on board for environmental hazard assessment of pharmaceuticals, focusing on the work done on diclofenac sodium. In fact, while traditional and regulatory Predicted No Effect Concentrations (PNECs) are usually based on the so-called “conventional” endpoints such as mortality and sublethal endpoints (e.g. growth, reproduction, development), it is here proposed to compare how the inclusion of less conventional endpoints may drive differently the hazard assessment. These endpoints depict different complexity scales as regards space (laboratory versus mesocosm data) and as regards biological organisation (community, population, individuals, cellular, biochemical). Applying this methodology, the so-called early-warning endpoints are compared to effects observed at community or populational level. Then, different PNECs are derived and presented : “traditional PNECs” covers conventional endpoints for at least three trophic levels (algae, crustaceans and fish), while “non conventional PNECs” may take account of the mesocosm study data obtained during the project but also of biomarkers response (e.g. biomarkers of effects such as immunotoxicological or respiratory burst effects).