Evaluation of non-opioid analgesic toxicity and their effects on native and invasive species of crustaceans (Gammaridae, Gammarus)

Humans widely use pharmaceuticals due to their availability, effectiveness, quick pain relief, and ability to improve well-being and health conditions. Their presence in aquatic environments, even in small doses, leads to serious ecological disturbances and alterations in trophic chains. This study aimed to assess the mortality and mobility of native Gammarus pulex and invasive Gammarus tigrinus under exposure to the nonopioid analgesics paracetamol, ibuprofen, ketoprofen, and a pharmaceutical mixture, as well as to determine their acute toxicity and impact on both species. At the 24 th and 96 th h of exposure, the highest increase in mortality was observed, most likely linked to shock caused by the sudden appearance of pollutants and the duration of exposure. Mortality was influenced not only by exposure time but also by the type of pharmaceutical. Paracetamol was the most lethal for both native and invasive species, though 100% mortality was recorded after 96 h of exposure. At a concentration of 5000 mg/L, all organisms died within 24 h. G. tigrinus , despite its broader ecological tolerance to pollution and resistance to environmental changes, responded to the presence of pharmaceuticals like G. pulex . Regarding survival, the ibuprofen–ketoprofen mixture in a 1:1 ratio was the least lethal for G. tigrinus , while ketoprofen alone was the least lethal for G. pulex . The availability and widespread use of over-the-counter pharmaceuticals, combined with the lack of systematic monitoring of aquatic environments, pose serious challenges to aquatic organisms in the context of pharmaceutical pollution in water habitats.