PubMed · 2026-02-15
Researchers mapped how antibiotics move through city sewer systems, finding that veterinary and shared human-veterinary antibiotics are the most common, with one antibiotic (Ofloxacin) posing measurable ecological risk near hospitals. Antibiotics from livestock appear to reach sewers through the food chain, not just direct discharge.
Shared human-and-veterinary antibiotics averaged 378 ng/L in sewer water, roughly 7 times higher than veterinary-only antibiotics at 52.6 ng/L.
Ofloxacin posed medium ecological risk (risk quotient 0.1–1.0) in sewers near hospitals, the only antibiotic to cross that threshold.
Strong statistical links between veterinary and human-veterinary antibiotic loads suggest livestock farming is transferring antibiotic residues into urban sewers via the food chain.