Antibiotics Found In Rivers At Up To 300 Times Over 'Safe' Levels

A new study warns that antibiotics levels in rivers around the world are at levels up to 300 times higher than what is considered safe. The research involved the 14 most commonly used antibiotics, which were found at 65-percent of monitored rivers across 72 countries. An antibiotic called metronidazole, which is commonly used for bacterial infections, was found in the highest concentrations.

The research comes out of the University of York, which reports that this is the first global study of its kind. Rivers in a total of 72 countries across half a dozen continents were evaluated; 65-percent of them contained antibiotics, including one site in Bangladesh, where metronidazole was found at 300 times the concentration considered safe.

Though metronidazole had the highest concentration margin, the antibiotic ciproflaxacin was the most frequent medicine to be found exceeding safe levels, and trimethoprim was the most commonly detected antibiotic overall at 307 of 711 sites.

The AMR Industry Alliance defines various antibiotic safety levels at falling between 20 – 32,000 ng/l, depending on substance. The new study used those guidelines when evaluating antibiotic levels in the world's rivers. The excessive antibiotic levels were found in a substantial number of places, making this a worldwide problem, but some regions had higher levels than others.

According to the study, rivers in Africa and Asia had the highest number of test sites exceeding safe levels. Other regions that had excessive antibiotic concentrations in rivers included North and South American and Europe. Topping the 'highest levels' rivers were sites in Bangladesh, Pakistan, Kenya, Ghana, and Austria.