Medical drugs are polluting rivers from Norway to Nairobi

Of all the types of water pollution, from plastic to pesticides, there is one that hasn’t always captured quite the same attention over its environmental and public health impacts. That’s changing with the Global Monitoring of Pharmaceuticals Project, an initiative that’s mapping the drugs found in rivers across the world.

A recent paper from global collaborators of the project, led by the University of York in the United Kingdom, provides one of the most comprehensive looks yet at how antibiotics and other commonly used drugs taint the water and often approach toxic levels.

The study includes samples taken from 258 rivers in 104 countries, representing every continent on the planet. The water samples were tested for 61 different kinds of drugs, used for controlling type 2 diabetes, high blood pressure, allergies, seizure disorders and more.

Of more than 1,000 sampling sites included in the study, roughly a quarter of them had at least one drug present at levels greater than the concentrations considered safe for aquatic organisms, or that are an antimicrobial resistance concern.

“Pharmaceutical pollution poses a global threat to environmental and human health,” said the authors, whose work was published in the journal Proceedings of the National Academy of Sciences (PNAS). And while that’s been known for quite some time, project co-leader Dr. John Wilkinson says this is the first time that the extent of pharmaceutical pollution has been assessed in much of the developing world.

“We’ve known for over two decades now that pharmaceuticals make their way into the aquatic environment where they may affect the biology of living organisms,” Wilkinson said. “But one of the largest problems we have faced in tackling this issue is that we have not been very representative when monitoring these contaminants, with almost all of the data focused on a select few areas in North America, Western Europe and China.”

The new research reveals that some of the highest levels of drugs concentrated in rivers are in sub-Saharan Africa and parts of Southeast Asia. In Barisal, Bangladesh, the level of the antibiotic metronidazole at one sampling site was more than 300 times higher than the safe target.

Lahore in Pakistan, La Paz in Bolivia, and Addis Ababa in Ethiopia all had among the highest drug levels in the world, with five of the 15 locations in the 90th percentile all in major African cities.

By comparison, Madrid was the only city among them that was located in Europe or North America.

“Through our project, our knowledge of the global distribution of pharmaceuticals in the aquatic environment has now been considerably enhanced,” says Wilkinson. “This one study presents data from more countries around the world than the entire scientific community was previously aware of.”

The researchers found that places without adequate wastewater infrastructure, where trash or septic tanks are dumped along river banks, are most likely to have the highest levels of pharmaceutical pollution. Places with older populations and higher levels of poverty and unemployment also saw more drugs in their water.

“We demonstrate that pollution of the world’s rivers by medicinal chemicals is a global problem that: 1) poses risk to both aquatic ecology and potential antimicrobial resistance selection and 2) may risk achievement of the United Nations Sustainable Development Goal 6.3 by 2030,” the authors warn.

“As we move toward 2030, the new paradigm in environmental monitoring must involve a global, inclusive, and interconnected effort.”