43% of world’s rivers contain dangerous levels of prescription drugs

There’s more than trash and microplastics polluting the world’s waterways.

Close to half of all rivers on the planet are contaminated by pharmaceutical drugs, a new study has shown.

Researchers found 23 active ingredients exceeding “safe” concentrations, including those in antidepressants, antihistamines, stimulants, benzos and painkillers, in 43.5% of the 1,052 individual samples taken in 104 countries.

Out of 137 broad sites where multiple samples were taken throughout, 34.1% of them had at least one location where concentrations were of “ecological concern,” researchers wrote.

“Our findings show that a very high proportion of rivers around the world are at threat from pharmaceutical pollution,” said the study’s co-author Alejandra Bouzas-Monroy, a doctoral student at the University of York in the UK.

“We should therefore be doing much more to reduce the emissions of these substances into the environment,” said Bouzas-Monroy, whose new report was published in the journal Environmental Toxicology and Chemistry on Wednesday.

It’s “truly the first global assessment” of its kind, added Bouzas-Monroy, whose team analyzed samples littered throughout Europe, North America, Australia, Asia and Africa.

Pharmaceuticals end up in our rivers, lakes and streams a few ways, according to the US Geological Survey, including through waste discharged by pharmaceutical manufacturing facilities, as well as from farms, where livestock regularly receive drugs to stave off illness and disease, and from people, who expel the drugs that their bodies don’t metabolize. (Obviously, dumping pills in the toilet is another unnecessary way humans contribute to the problem.)

The agency conducted its first major study on the subject in 2002, finding that seven or more different chemicals were present in at least half of the streams tested; 34% revealed 10 or more of these substances. In 2019, they also tested 1,120 wells and springs throughout the US, where drugs like carbamazepine (an anticonvulsant), sulfamethoxazole (an antibiotic), meprobamate (a tranquilizer) and hydrocortisone (an antihistamine) were among the most commonly found.

In 2008, the Associated Press conducted their own investigation of drinking water from 24 major metropolitan water suppliers and found trace amounts of a variety of prescription drugs; meanwhile, 34 other stations declined to participate in the AP survey as they do not regularly test for such chemicals in their own water supply.

Scientist aren’t sure what the health consequences of longterm, low-level exposure to various drugs may be. Of course, the first victims are fish and other aquatic life, whose biological processes may be disrupted by large doses of human drugs.

Furthermore, the overabundance of antibiotics in the environment has been a prominent concern among scientists who warn that it’s contributing to antimicrobial resistance, a k a “superbugs.”

“Overall, the results show that API [active pharmaceutical ingredients] pollution is a global problem that is likely negatively affecting the health of the world’s rivers,” concluded researchers of the new global report. “Work is urgently needed to tackle the problem and bring concentrations down to an acceptable level.”