Antibiotics make their way into the environment in many ways. Sources of antibiotic pollution include the waste from large-scale animal farms and the wastewater from hospitals, municipalities, and antibiotic manufacturing.
A new study has discovered concentrations of antibiotics in some of the world’s rivers exceed safe levels by up to 300 times. In the project, researchers looked for 14 commonly used antibiotics in rivers in 72 countries across six continents. They found antibiotics at 65% of all the sites they examined.
The antibiotic ciproflaxacin was the compound that most frequently exceeded safe levels, surpassing that threshold in 51 places. The antibiotic metronidazole exceeded safe levels by the biggest margin. Concentrations of this antibiotic at one site in Bangladesh was 300 times greater than the safe level. The most prevalent antibiotic was trimethoprim. It was detected at 307 of the 711 sites.
Some of the world’s most iconic rivers were sampled as a part of this study, including the Danube, Mekong, Seine, Thames, Tiber and Tigris.
The project, which was led by the University of York, found that high-risk sites were often located near wastewater treatment systems, waste or sewage dumps, and in some areas of political unrest.
Safe levels for antibiotics, which were recently established by the AMR Industry Alliance, range from 20,000 to 32,000 nanograms per liter depending on the compound.
According to the research team, solutions to the problem of antibiotic contamination should include infrastructure investment, tighter regulation, and the remediation of already contaminated sites.
Photo, posted October 7, 2013, courtesy of Nicola via Flickr.