Ibuprofen and diclofenac in the marine environment - a critical review of their occurrence and potential risk for invertebrate species

Abstract

The presence of the two main non-steroidal anti-inflammatory drugs (NSAIDs), diclofenac (DCF) and ibuprofen (IBU), in marine and estuarine systems has been reported. Although the available information about the toxicity of these compounds in aquatic organisms has increased in recent years, the database about marine organisms, specifically invertebrates, is limited. Consequently, the assessment of potential risks posed by these compounds to aquatic species should be improved, given their relevance for aquatic life and the trophic chain. To fill this gap, we analyze the potential risk of IBU and DCF in marine invertebrates. To assess the risk, the database was built with available information from the scientific literature about the occurrence, bioaccumulation, and toxicity of both compounds in the estuaries and marine environments. Risk assessment of both compounds in these environments is scarce and based essentially on their acute toxicity. Data compiled in this review, including environmental concentrations and toxicity thresholds, were used to calculate risk quotients and classify the risk for invertebrate communities in coastal areas with different contamination levels. The results indicated a higher risk for DCF than IBU. Additionally, the simultaneous presence of the two NSAIDs in the aquatic environment increases the risk for exposed organisms. The use of classical methods (e.g., biochemical markers, gene expression), new approaches (e.g., adverse outcome pathway, AOP), and omic techniques has contributed to understanding the underlying toxicity mechanisms and improving the risk assessment. However, in a global change scenario involving multiple drivers and pressures such as ocean acidification, heat waves, climate change, etc., the risk assessment for these emerging pollutants needs improvement. This can be achieved by increasing our knowledge about the metabolic pathway and biotransformation routes of these compounds in marine species and understanding how these changes can affect the bioaccumulation, toxicity, fate, and behavior of both NSAIDs.