This is the first global estimate of river pollution caused exclusively by human antibiotic consumption. The research team, using a contaminant fate model validated with data from nearly 900 river locations worldwide, calculated that around 8,500 tonnes of antibiotics—approximately one-third of all antibiotics consumed by people annually—are discharged into river systems. Many of these pharmaceutical residues persist even after passing through wastewater treatment systems.
Although the concentrations of individual antibiotics are often very low and difficult to detect, researchers emphasized that long-term, cumulative exposure remains a concern. They concluded that even small, chronic doses in surface waters can pose risks to both environmental and human health, particularly through increased resistance and microbial disruption in aquatic ecosystems.
The study identified amoxicillin, the world’s most widely used antibiotic, as the compound most frequently associated with high-risk pollution levels. The issue is especially acute in regions such as Southeast Asia, where antibiotic use is increasing rapidly and wastewater treatment infrastructure is limited. In addition to amoxicillin, the researchers flagged ceftriaxone and cefixime—both categorized under the World Health Organization’s “Watch” list due to their higher resistance potential—as commonly detected contaminants.
Significantly, the study focused solely on human antibiotic use, without accounting for other well-known sources of pharmaceutical pollution such as livestock production or factory discharge. The researchers noted that these additional sources would likely push environmental risk levels even higher than what the current model suggests.
The findings point to a critical need for improved environmental surveillance. The research team stressed that targeted monitoring programs are essential, particularly in regions identified as high-risk zones. Such efforts would help detect not only antibiotics, but also other chemical contaminants that currently go untracked in many parts of the world.
The study’s global contaminant model, HydroFATE, analyzed around 24 million kilometers of river networks, pinpointing antibiotic contamination hotspots in countries such as India, Pakistan, China, Nigeria, and across Southeast Asia. These areas are characterized by a combination of high population density, growing antibiotic consumption, and insufficient wastewater treatment infrastructure—factors that significantly increase both ecological and public health risks.
Researchers estimated that more than 750 million people live within 10 kilometers of river segments classified as high risk. In regions where these water sources are used for drinking, washing, or agriculture, chronic exposure to low levels of antibiotics becomes more likely. Such exposure has been linked to the rise of antibiotic-resistant bacteria in the human gut and may contribute to broader health issues, including metabolic disruption and immune system challenges.
The researchers emphasized that the study does not argue against the use of antibiotics, which remain essential for global health. Instead, the findings highlight the unintended environmental consequences of widespread antibiotic use. The study calls for mitigation and management strategies that could help reduce the ecological footprint and minimize the contribution to antimicrobial resistance.
The findings underscore the need for a coordinated and layered response. This includes expanding wastewater treatment capabilities, tightening discharge limits for pharmaceutical pollutants, and embedding environmental risk considerations into how antibiotics are regulated and approved. Currently, most treatment plants are not equipped with the advanced filtration systems needed to effectively remove drug residues from water.
For industries operating in water-intensive sectors—such as pharmaceuticals, food production, agriculture, and manufacturing—these insights bring growing responsibility. With global antibiotic consumption projected to increase by 200% by 2030, companies face mounting operational, regulatory, and reputational pressure to implement sustainable water practices and invest in advanced treatment technologies.
