Adverse Effects Induced by Nonsteroidal Anti-inflammatory Drugs on Freshwater Invertebrates

Nonsteroidal anti-inflammatory drugs (NSAIDs) are a group of molecules representing one of the most relevant therapeutic class found in the aquatic ecosystems worldwide. NSAIDs are commonly and extensively used for their analgesic, antipyretic and anti-inflammatory properties to cure pain and inflammation in both human and veterinary therapy. Because of the huge, continuative and increasing use, as well as their specific pharmacokinetic properties, after medical use they are excreted in their native form or as metabolites and enter the aquatic ecosystems. A number of monitoring surveys has reported levels of NSAIDs exceeding 1 μg/L in influent and effluents of Wastewater Treatment Plants (WWTPs), while lower concentrations have been found in surface waters, ranging in the ng/L – μg/L range. Among NSAIDs, paracetamol, diclofenac, and ibuprofen are the most detected therapeutics found in aquatic ecosystems. Although the concentrations of these molecules in surface waters are quite low, their high biological activity might confer them a potential toxicity towards non-target aquatic organisms. The present chapter aims at reviewing the adverse effects induced by paracetamol, diclofenac, and ibuprofen towards different freshwater invertebrates belonging to different taxa. Although acute toxicity of paracetamol, diclofenac, and ibuprofen occur only at high, unrealistic concentrations, sublethal effects were caused by low, environmentally relevant concentrations of these drugs. For these reasons, further studies represent a priority in order to enlarge the knowledge on NSAID toxicity towards aquatic organisms and to shed light on their real ecological hazard towards aquatic communities.