Antibiotics taint two out of every three rivers sampled as part of a big new survey. Scientists made the finding while testing water from 165 rivers across 72 countries. Many of most polluted sites were in Asia and Africa. Until now, there had been little testing in these areas for drugs in water.
The new data are a big concern. Bacteria that can’t be killed by antibiotics pose a large and growing threat to health. Doctors call these bacteria “superbugs.” As microbes encounter drugs in the environment, many will evolve changes. Called mutations, some of these may allow the germs to survive the drugs. Later, people infected with those microbes may find themselves at risk of life-threatening disease.
It doesn’t matter that some of these pollution problems are occurring in far-off sites around the world. People should still be as concerned about resistance evolving in these places as they are about it developing in their own backyards, says William Gaze. He’s a microbial ecologist in England who works at the University of Exeter Medical School. Even if wealthy countries wipe out antibiotic pollution, drug-resistant microbes can hitch a ride to those countries. They can arrive with sick travelers. They might move around the world in migrating birds. They might even arrive in imports of animal-based foods, says Gaze. “It’s a global problem,” says this scientist, who was not involved with the new survey. That’s why, he adds, “We need global solutions.
Alistair Boxall and John Wilkinson work in England at the University of York. Together, they tested water from 711 sites. And 470 of them contained at least one antibiotic.
About one in every seven of the sites tested — 111 in all — contained unsafe levels of the drugs. That judgment is based on guidelines by the AMR Industry Alliance. It’s a global group of biotech and drug companies. It has set safety thresholds. And those are based on data showing what levels of a drug would neither kill algae nor promote drug resistance in bacteria.
“I don’t think I was expecting the degree of [high] concentrations that we saw,” says Boxall, who is an environmental chemist. “That was quite eye-opening.”
He and Wilkinson shared their findings in a pair of papers presented on May 27 and May 28. They spoke in Helsinki, Finland at a meeting of the Society of Environmental Toxicology and Chemistry