Global pharmaceutical pollution in waterways: Insights from sewage treatment point sources

The global presence of pharmaceutical residues in sewage is a growing environmental concern, driven by human excretion, improper disposal, and industrial waste streams. This study synthesized data from meticulously selected 101 peer-reviewed publications to evaluate the occurrence of 20 pharmaceuticals in sewage influent and effluent as a primary point source of pollutants across diverse geographical regions, analyzed based on Asia, America, Europe, Africa and Australia. The highest cumulative concentrations of pharmaceuticals, particularly analgesics/anti-inflammatory drugs, were observed in North and South America, while most of the publications were dominantly published under the European region. Diclofenac, ibuprofen, sulfamethoxazole, and ciprofloxacin were the most frequently detected compounds and were found at high concentrations, exceeding 100,000 ng/L in the influent of some STPs. Ibuprofen and naproxen demonstrated high removal efficiencies, consistently exceeding 80%, with no instances of negative removal observed. Atenolol, simvastatin, and valsartan exhibited substantial removal, though some STPs showed increased effluent concentrations. Contradictorily, diazepam, carbamazepine, azithromycin, and clindamycin demonstrated persistence through the conventional treatment processes, as evidently shown by the predominantly negative removal percentages. The occurrence of pharmaceuticals in sewage treatment plants (STPs) represents a significant global risk to both ecosystems and human health. Ecotoxicological risk assessments, based on hazard quotients (HQs) derived from the maximum measured concentrations, revealed heightened vulnerability among primary producers and consumers in aquatic environments, with higher trophic levels facing risks from bio-accumulative compounds. This pervasive micropollutant contamination emphasizes the critical need for improved wastewater treatment technologies, rigorous regulatory frameworks, and sustainable pharmaceutical disposal practices to minimize ecological impacts.