Nationwide monitoring of selected antibiotics: Distribution and sources of sulfonamides, trimethoprim, and macrolides in Japanese rivers

► Nationwide survey of human and veterinary antibiotics in 37 rivers was conducted. ► Antibiotics concentrations were correlated with sewage markers. ► Veterinary antibiotics signals were overwhelmed by those of human antibiotics. ► Target antibiotics in Japanese rivers are derived mainly from urban sewage. ► Animal antibiotics are unlikely to be readily discharged to surface waters.