More than a quarter of world’s rivers poisoned by drugs

By Mark Waghorn via SWNS

More than a quarter of the world's rivers are poisoned with over-the-counter and prescription drugs, according to new research.

Concentrations have reached "potentially toxic levels" - endangering people, fish and other wildlife, say scientists.

Medications that target hormones for instance, for example, have induced sex changes in marine animals.

Project co-leader Dr. John Wilkinson, of York University, said: "Environmental exposure to active pharmaceutical ingredients (APIs) harms ecosystems and, potentially, human health through mechanisms such as antimicrobial resistance.

"We've known for over two decades now that they make their way into the aquatic environment where they may affect the biology of living organisms.

"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 most comprehensive study to date looked at 258 rivers across the globe - including the Thames in London and the Amazon in Brazil.

It found pharmaceutical pollution is contaminating water on every continent. A total of 54 sampling locations were selected in the UK.

Drugs were detected in all - apart from four in remote Snowdonia in Wales. The most contaminated was the River Clyde in Glasgow.

Dr. Wilkinson said: "Concentrations in the UK were in line with what we've observed more generally across Europe."

The most frequently detected drug in British waterways was carbamazepine prescribed for epilepsy - found at 69 percent of the sites.

Dr. Wilkinson said: "There are 19.5 million people who live across the cities where we did monitoring work in the UK (London, Leeds, York, Glasgow, Northern Wales and Belfast.)

"That's nearly a third of the population."

The world's worst hit regions are the ones that have been analysed the least - sub-saharan Africa, South America and parts of southern Asia.

Less than a quarter of waste water is treated - and technology is unable to filter out most pharmaceuticals.

There was a strong link with socio-economic status - with lower-middle income nations most vulnerable.

Local communities with an older average age and high unemployment and poverty rates were also more at risk.

Dumping of rubbish along banks and septic tank contents in rivers, poor drugs manufacturing and inadequate wastewater management were other key factors.

Over one-in-four sites contained pharmaceutical effluence that was likely harm the environment.

The chemical cocktails were a mix of drugs ranging from antibiotics to beta blockers, hay fever pills and anti-psychotics.

It's hoped increased monitoring will lead to strategies that limit the effects.

The first global investigation of its kind also included noteworthy rivers such as the Mississippi and the Mekong.

Water samples were even obtained from a village in Venezuela's Amazonian where modern medicines are not used.

They were compared to those from some of the busiest cities on the planet - like London, New York, Las Vegas, Delhi, Lagos and Guangzhou.

Areas of political instability such as Baghdad, the Palestinian West Bank and Yaoundé in Cameroon were also included.

The climates varied from high altitude alpine tundra in Colorado and polar regions in Antarctica to Tunisian deserts.

A state-of-the-art scanner at York identified propranolol, a beta-blocker for heart disease, and loratadine which is taken for allergies.

Others included the common antibiotics sulfamethoxazole and ciprofloxacin for bacterial infections.

They can disrupt organisms' reproductive capabilities, alter behaviour or physiology - and even change heart rate.

Dr. Wilkinson said: "The most frequently detected APIs were the anti-epileptic drug carbamazepine, the antihyperglycaemic drug metformin - and caffeine.

"A quarter of all sampling sites had at least one API exceeding levels considered safe for aquatic organisms or implicated in antimicrobial resistance.

"The results demonstrate the global scale of pharmaceutical pollution in the environment."

Previous studies have monitored APIs in rivers. But these have ignored many of the countries of the world.

They have also measured only a select few contaminants - and employed different analytical methods.

Cumulatively, this has made it difficult to quantify the scale of the problem from a global perspective.

Dr. Wilkinson added: "With 127 collaborators across 86 institutions worldwide, the Global Monitoring of Pharmaceuticals Project is an excellent example of how the global scientific community can come together to tackle large-scale environmental issues.

"Through our project, our knowledge of the global distribution of pharmaceuticals in the aquatic environment has now been considerably enhanced.

"This one study presents data from more countries around the world than the entire scientific community was previously aware of - 36 new countries to be precise where only 75 had ever been studied before.”

The approach could be expanded in future to include sediments, soils and biota - allowing for the development of global-scale datasets on pollution.

It's feared the amount of drugs leaching into waterways will increase by two-thirds before 2050 - endangering freshwater ecosystems.

The findings were published in the journal Proceedings of the National Academy of Sciences (PNAS).