Beyond Humans: Effects and Consequences of Illicit Drugs in the Aquatic Environment

The use of illicit drugs is one of the most serious problems today, both from a social and environmental point of view. After cannabis, one of the most widely used drugs is cocaine. Global cocaine abuse has led the scientific community to include it among emerging contaminants, as it has been detected in increasing quantities in various environmental matrices. In particular, numerous studies have detected the presence of cocaine in aquatic environments, with concentrations ranging from 0.13 ng L−1 to 537 ng L−1, highlighting the potential implications for the organisms inhabiting these ecosystems. The consequences of exposure on the main inhabitants of the seawater and freshwater ecosystems, such as shellfish, crustaceans, and fish, are primarily attributable to physiological, biochemical, and behavioural alterations. These changes manifest as oxidative stress and neurotoxicity, which can lead to impaired growth, reproduction, and even survival of organisms. Furthermore, the ability of the substance and its metabolites to accumulate in the tissues of exposed organisms is of particular concern, with potential effects on ecosystems and human health. This review aims to provide an updated summary of the available knowledge on the ecotoxicological effects of cocaine in aquatic ecosystems, highlighting existing knowledge gaps and the need for further research.