Assessment of Non-Steroidal Anti-Inflammatories in River Waters of Northeastern of Brazil: Occurrence and Environmental Risk

Abstract

The environmental impact of pharmaceuticals is a significant concern, as understanding their presence, spread, and harm in coastal regions remains limited. The occurrence of non-steroidal anti-inflammatory drugs (NSAIDs), namely, mefenamic acid (MFN), diclofenac (DCF) and naproxen (NPX) were studied in river waters. Four sample collections were carried out in five points in the dry and rainy seasons. Solidified floating organic drop microextraction (SFODME) coupled with high performance liquid chromatography using diode array detection (HPLC-DAD) were applied to quantify the presence of MFN, DCF and NPX in river water samples. DCF had the highest concentration (640 ng L-1), followed by NPX (410 ng L-1). MFN was not detected in any point within the used working range (limit of detection (LOD) of 0.07 µg L-1). Additionally, an assessment was conducted to evaluate the environmental risk associated with the pharmaceuticals detected in freshwater, specifically in various organisms including algae, mollusks, amphibians, fish, and cnidarians, spanning different trophic levels. The ecotoxicological assessment showed risks ranging from low to high, indicating deleterious effects on several exposed species. No high environmental risk was detected in the sampling areas. Although no immediate negative effects were detected, the potential impact on non-target species should not be disregarded.