Country-level antibiotic risk assessment in the multiple environmental matrices based on decennial data.

The overuse of antibiotics has led to widespread environmental detection. However, country-level antibiotic risks from a global perspective remain unclear, highlighting a crucial need for antibiotic management worldwide. This study elucidated a global assessment of antibiotic detection frequencies and concentrations across various countries, compared detection levels of antibiotic classifications across compartments in representative countries, and conducted a risk assessment based on predicted no-effect concentrations (PNECs) for antibiotic resistance and minimum inhibitory concentrations (MICs) relevant to microbial nitrogen cycling. A decennial dataset comprising 431,441 records for 137 antibiotics across eight environmental compartments in 45 countries was analyzed. Results showed that Kenya (199 %) had the highest cumulative detection frequencies of four aqueous media. Wastewater from WWTPs (mean: 19.7 ng/L) and animal manure (mean: 2.6 μg/kg) exhibited the highest levels in aqueous and solid media, respectively. From sources to receptors, the highest antibiotic detections and concentrations were found in wastewater from WWTP, where quinolones dominated in France and the USA, and sulfonamides in Kenya (175-357 detections, median: 137-580 ng/L). Similarly, in surface water, sulfonamides were significant in Kenya and Vietnam, quinolones in Kenya (290-2049 detections, median: 32-70 ng/L). From the perspective of cumulative risk, Malaysia, China, and Canada are ranked the top three for both PNECs risk (81 %-191 %) and MICs risk (211 %-236 %). Whether for PNECs or MICs, sulfonamides are the most exceedance-prone antibiotic class across countries and also the highest-risk antibiotic class (median: 33 %). According to the total risk results from different countries, Malaysia (402 %) has the highest risk, followed by Canada (317 %) and China (315 %). The highest antibiotic risks were observed in Asia (medium SDG score), followed by Europe and the Americas (high SDG score), and Africa (low SDG score).