Ibuprofen and Diclofenac: Effects on Freshwater and Marine Aquatic Organisms – Are They at Risk?

Pharmaceuticals are included in the group of emergent pollutants due to their characteristics and potential negative effects. They remain mostly unregulated or are undergoing currently some sort of regularization process. Diclofenac, for instance, has been included in a watch list of substances for European Union-wide monitoring and the priority list of the Water Framework Directive (WFD) of the European Union. Nonsteroidal anti-inflammatory drugs (NSAIDs) are a varied and chemically heterogeneous group of mainly anti-inflammatory, analgesic, and antipyretic drugs, reducing symptoms of inflammation, pain, and fever, respectively. They are widely employed and have been detected in freshwater, seawater, and sediment. Nevertheless, they are found as mixture instead of single compounds. In this chapter, we have tried to summarize how to assess the risk due to the occurrence of pharmaceuticals in aquatic ecosystems. We have focused on the mixture of diclofenac and ibuprofen using acute and sublethal toxicity data for different aquatic species. It has been presented new strategies as adverse outcome pathway to improve the understanding of the toxicity of these compounds. Although gaps of the information are pointed out, the risk levels associated with the occurrence of these compounds in aquatic ecosystems will range between no risk or high risk, depending on concentrations and environmental conditions.