A global study on contamination of rivers by antibiotics found that the world's rivers are contaminated with antibiotics. Dangerous levels of contamination were most frequently found in Asia and Africa, with sites in Kenya, Ghana, Nigeria, Pakistan, and Bangladesh exceeding safe levels by the greatest degree. The study is the first of its kind.
The study, carried out by researchers at the University of York in the UK, analyzed samples from rivers in 72 countries and found that antibiotics were present in 65% of them. Researchers looked for 14 commonly used antibiotics in their samples. Of the 14 antibiotics, 3 stood out the most: metronidazole, trimethoprim, and ciprofloxacin.
Metronidazole, a drug used to treat bacterial infections including skin and mouth infections, exceeded safe levels by the biggest margin, with concentrations at one site in Bangladesh 300 times greater than the ‘safe’ level. Trimethoprim, used mainly for urinary tract infections, was the most prevalent antibiotic found at 43% of the river sites tested. Ciprofloxacin, a broad-spectrum antibiotic, was the compound that most frequently exceeded safe levels, surpassing the safety threshold in 51 places. The data was collected from 711 sites.
According to the researchers, high-risk sites were typically next to wastewater treatment plants, waste or sewage dumps and in some areas of political turmoil. Professor Alistair Boxall, Theme Leader of the York Environmental Sustainability Institute, said, “The results are quite eye-opening and worrying, demonstrating the widespread contamination of river systems around the world with antibiotic compounds.
"Many scientists and policymakers now recognise the role of the natural environment in the antimicrobial resistance problem. Our data shows that antibiotic contamination of rivers could be an important contributor. 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."
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