A new study led by McGill University has revealed that rivers around the world are being contaminated by antibiotics from human use, creating risks for aquatic life and contributing to antibiotic resistance.

Published in PNAS Nexus, the study estimates that about 8,500 tonnes of antibiotics nearly one-third of global human consumption end up in river systems every year. Even after passing through wastewater treatment, these substances continue to pollute rivers in many areas.

While the concentrations of antibiotics in most rivers may seem low, their long-term presence could still harm both the environment and human health. The study identified amoxicillin, the most commonly used antibiotic globally, as the most likely to reach risky levels, especially in regions like Southeast Asia where antibiotic use is increasing and wastewater treatment is limited.

The research also highlights that the study only considered antibiotics from human use, excluding those from livestock or pharmaceutical factories, which also contribute to river contamination. The findings point to the need for better wastewater management and monitoring of antibiotic pollution to protect ecosystems and combat antimicrobial resistance.