Rivers across the world are being polluted by antibiotics, confirms a new global study from the University of York in the United Kingdom.
The study, the first and largest of its kind, analyzed 711 samples from rivers across 72 countries, and found common antibiotics used to treat bacterial infections in people and livestock in 65% of the samples.
Researchers presented their findings at a conference held by the Society of Environmental Toxicology and Chemistry in Finland on Monday.
The scientists revealed that 111 sites analyzed contained dangerous levels of antibiotics, but the samples with the most unsafe levels of drugs present were taken from Asian and African countries such as Bangladesh, Kenya, Ghana, Pakistan, and Nigeria.
In about 51 sample sites, Ciprofloxacin, a commonly prescribed drug for intestinal and urinary tract infections, surpassed safety standards by large margins. And in Bangladesh, the location with the most concerning samples, the antibiotic Metronidazole, used to treat skin and mouth diseases, exceeded the safety levels determined by professionals measuring and combating anti-microbial resistance, by 300%.
"The results are quite eye opening and worrying, demonstrating the widespread contamination of river systems around the world with antibiotic compounds,” Professor Alistair Boxall, a scientist at the York Environmental Sustainability Institute, said in a statement.
At one site in Kenya, the toxic levels of antibiotics led to the death of all fish in the water body from which the study’s sample was drawn. However the presence of antibiotics in water bodies not only poses a threat to wildlife, but also contributes to the growing problem of antimicrobial resistance.
Antibiotic resistance occurs when bacteria stop responding to medicine, leading to increased medical costs, extended stays in hospitals, diminished effectiveness of drugs, and even potential death.
According to a recent report by the World Health Organization (WHO), drug-resistance is a growing concern that causes at least 700,000 deaths annually, including 230,000 deaths from strains of tuberculosis resistant to multiple drugs.
If no successful measure is adopted, the reports estimates that 10 million people could lose their lives to drug-resistant diseases by 2030.
"More resistant infections don't just mean you or someone you care about is more likely to die from one, they also mean healthcare will get even more expensive," Bill Hanage, an associate professor of epidemiology at Harvard's Chan School of Public Health, told CNN.
“Many of the procedures we take for granted in medicine, from cancer treatments to surgeries, depend on our ability to handle infections that happen in the course of treatment."
The main causes of resistance were previously identified as the over-prescription of antibiotics and slow development of new drugs, and while those factors remain major contributors, the new research identified additional environmental factors as key elements causing resistance.
"Many scientists and policy makers now recognize the role of the natural environment in the antimicrobial resistance problem. Our data show that antibiotic contamination of rivers could be an important contributor [to drug resistance]," Boxall said.
"Solving the problem is going to be a mammoth challenge and will need investment in infrastructure for waste and wastewater treatment, tighter regulation and the cleaning up of already contaminated sites."