Pharmaceuticals and personal care products (PPCPs) have raised concerns due to their potential impacts on aquatic organisms and ecosystems. Among the PPCPs, non-steroidal anti-inflammatory drugs (NSAIDs) have been detected frequently in water bodies worldwide. Ibuprofen and naproxen, two commonly used NSAIDs, are released into the environment through a diverse route and are often incompletely removed in wastewater treatment. Despite their low concentrations, these drugs can persist and accumulate in aquatic ecosystems, threatening native species. The effects of environmentally relevant concentrations of IBU and NPX were assessed using Daphnia carinata as a model native test species. The measured endpoints included mortality, reproductive parameters, feeding and heart rates. IBU and NPX exposure caused a significant effect on reproduction (p<0.05), decreasing the number of broods and the total number of neonates at all concentrations of both NSAIDs. Also, the feeding rate of the daphnids was affected at 100 µg/L of NPX. No mortality was recorded after 21 days, and heart rate was not affected after 48h exposure.
Overall, this research provides valuable insights into the ecotoxicological effects of ibuprofen and naproxen, indicating that even at low concentrations, both NSAIDs may cause deleterious effects on reproduction and feeding in Daphnia carinata. The findings of this study emphasize the need for further research and monitoring of NSAIDs in the Australian aquatic environment. The incomplete removal of these drugs by wastewater treatment plants could impact biodiversity, and this research highlights the importance of improving treatment protocols to minimize their release into water bodies.