Global antibiotic hotspots and risks: A One Health assessment.

Antibiotics are increasingly prevalent in global environments, driving antimicrobial resistance and disrupting microbial cycling. These impacts pose threats to human, animal, and environmental health. Therefore, addressing this emergent issue necessitates a One Health framework that integrates these interconnected dimensions. Here we systematically review 137 antibiotics across diverse global environmental compartments. We find that sulfonamides, macrolides, quinolones, and tetracyclines are globally ubiquitous, particularly prevalent in Asia and Africa, whereas β-lactams dominates in Europe. Hierarchical clustering revealed ten priority antibiotics in liquid phases and eight in solid phases requiring urgent attention. Regional analysis indicated the highest antibiotic concentrations within wastewater treatment plant liquids in the Americas and surface waters in Africa, with generally lower levels detected in Asia and Europe. Utilizing a One Health assessment framework, we integrated Predicted No-Effect Concentrations for antibiotic resistance selection (PNEC) relevant to human and animal health with Minimum Inhibitory Concentrations (MICs) affecting microbial nitrogen cycling processes. Risk assessment highlighted wastewater treatment plant liquids (20 % average exceedance) and animal manure (44 % average exceedance) as the most critical compartments. Africa exhibited the highest overall risk, averaging a 53 % exceedance rate. Notably, ciprofloxacin and ofloxacin in liquid phases, as well as enrofloxacin and norfloxacin in solid phases, emerged as antibiotics posing significant One Health risks. This study advances our understanding of antibiotic distribution globally, offering a foundation for targeted interventions to mitigate antibiotic-related risks across human, animal, and environmental health sectors.