Occurrence of pharmaceuticals, illicit drugs and PFAS in global surface waters: A meta-analysis-based review.

Emerging contaminants (ECs) have been recognized as a new class of water contaminants and their occurrence in surface water is a concern for ecosystems and society. The aim of this study is to provide a comprehensive systematic review based meta-analysis of ECs in global surface waters and associated ecological risks. With a special focus on pharmaceuticals and illicit drugs (PIDs), and per- and polyfluoroalkyl substances (PFAS). Web of Science, Scopus, Google Scholar, and PubMed databases were screened to retrieve articles published between 2013 and 2024. One hundred-one articles comprising 714 datasets spanning 70 PIDs and PFASs in surface water across 46 countries were included in the meta-analysis study. Global PID concentrations ranged from 0.02 ng/L to 82,188 ng/L, with metformin (MFN) having the highest meta-analyzed median concentration of 729.4 ng/L. Antibiotics, analyzed separately revealed sulfonamides as the most detected. Our analysis showed that PIDs (including antibiotics) levels were in the upper quartiles in low-income settings where wastewater treatment is scarce, whereas in most situations where secondary treatments are utilized, their levels tended to remain in the lower quartile. Wastewater treatment beyond a secondary level can reduce these chemicals to levels which present little to no environmental impact. Global PFAS concentrations ranged from 0.01 ng/L to 311.25 ng/L with perfluoroalkylcarboxylic acids (PFCAs) being the most commonly occurring PFAS. Meta-analysis revealed that perflurohexanoic acid (PFHxA) had the highest meta-synthesized median concentration of 3.6 ng/L in surface waters. Environmental risk assessment revealed high risk (HQ ≥ 1) for the following: MFN, acetaminophen (APAP), ibuprofen (IBU), sulfacetamide (SAM) and lomefloxacin (LFX) and moderate risk (HQ ≥ 0.1) for perfluorododecanoic acid (PFDoA), perfluorotetradecanoic acid (PFTeDA) and perfluoroundecanoic acid (PFUnDA).