A McGill University-led study has discovered alarming levels of antibiotic pollution in rivers globally, emphasizing the need for robust monitoring and mitigation strategies to protect aquatic life and public health.
Millions of kilometers of rivers around the globe are contaminated by antibiotics at levels sufficient to promote drug resistance and harm aquatic life, according to a recent study led by McGill University. Published in PNAS Nexus, this study is the first to provide an estimate of the global scale of river contamination caused by human antibiotic use.
The research reveals that approximately 8,500 tonnes of antibiotics — nearly one-third of the global annual consumption — contaminate river systems each year, even after passing through wastewater treatment facilities.
“While the amounts of residues from individual antibiotics translate into only very small concentrations in most rivers, which makes them very difficult to detect, the chronic and cumulative environmental exposure to these substances can still pose a risk to human health and aquatic ecosystems,” lead author Heloisa Ehalt Macedo, a postdoctoral fellow in geography at McGill, said in a news release.
Using a global model validated by field data from nearly 900 river locations, the research highlighted that amoxicillin — the world’s most-used antibiotic — is prevalent at risky levels, especially in Southeast Asia where increasing use and inadequate wastewater treatment exacerbate the problem.
“This study is not intended to warn about the use of antibiotics — we need antibiotics for global health treatments — but our results indicate that there may be unintended effects on aquatic environments and antibiotic resistance, which calls for mitigation and management strategies to avoid or reduce their implications,” added co-author Bernhard Lehner, a professor in global hydrology in McGill’s Department of Geography.
Significantly, the study did not account for antibiotics from livestock or pharmaceutical factories, both of which are significant pollutant sources.
“Our results show that antibiotic pollution in rivers arising from human consumption alone is a critical issue, which would likely be exacerbated by veterinarian or industry sources of related compounds,” added co-author Jim Nicell, an environmental engineering professor at McGill. “Monitoring programs to detect antibiotic or other chemical contamination of waterways are therefore needed, especially in areas that our model predicts to be at risk.”
Source: McGill University