Potentially toxic levels of pharmaceutical drugs were found in a quarter of river locations that were examined across the world, a study found.
Researchers from around the world surveyed more than 1,000 locations on 258 rivers, including the Thames in London and other UK waterways.
The Amazon river in Brazil was also included in the study along with rivers in major cities such as Delhi, New York and Guangzhou.
Compounds linked to lifestyles
The assessment measured the presence of 61 pharmaceuticals, including some compounds also linked to lifestyles such as caffeine, and whether they were above levels where they could have an effect on the environment.
The study, published in the Proceedings of the National Academy of Sciences (PNAS), warns that pollution of the world’s rivers by medicinal chemicals is a global problem.
Pollution poses a risk to freshwater habitats and wildlife and potentially contributes to the build-up of antimicrobial resistance.
More from World
It also threatens global goals on water quality and pollution, the research warns.
Beta blockers, antibiotics and antidepressants found
The analysis, carried out at the University of York, found pharmaceutical pollution in rivers on every continent, with nicotine and cotinine, caffeine and paracetamol turning up everywhere including Antarctica.
An array of chemicals such as beta blockers, antibiotics, antidepressants, sleeping medication and antihistamines were found in rivers on all inhabited continents.
While most chemicals seen in rivers globally are lower than concentrations that could cause ecological effects, there were levels of contaminants that could pose a threat to environmental or human health in more than a quarter of the studied locations.
And some rivers are exposed to complex mixtures of chemicals.
Image: The Amazon was one of 258 rivers that were studied during the research
Contaminants found at potentially harmful concentrations at some sites included beta blocker propranolol and antibiotic ciprofloxacin.
For the study, water samples were obtained from sites spanning from a village in Venezuela, where modern medicines are not used, to cities ranging from Lagos to Las Vegas, along with areas of political instability such as Baghdad and the Palestinian West Bank.
Read more: ‘Chemical cocktail’ – Sewage, slurry and plastic coursing through English rivers, say MPs
The research found lower and middle income countries were the most polluted, while rubbish dumping along river banks, inadequate waste water infrastructure and pharmaceutical manufacturing and dumping of septic tank contents into rivers were the activities most associated with the issue.
The most polluted countries and regions of the world are the ones, such as sub-Saharan Africa, South America and parts of southern Asia, that have been researched the least.
UK’s most contaminated river
In the UK, the study looked at 54 sampling locations on 12 rivers, and detected pharmaceuticals in all but four sites in Snowdonia, Wales.
Image: The most contaminated site in the UK was the River Clyde in Glasgow
The most contaminated site in the UK was the River Clyde in Glasgow, but concentrations in UK rivers were in line with European sites more generally.
Co-leader of the project Dr John Wilkinson, from the University of York, said: “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.
“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.
“Through our project, our knowledge of the global distribution of pharmaceuticals in the aquatic environment has now been considerably enhanced.”
There needs to be global, inclusive and interconnected efforts to generate monitoring data needed to make decisions on how to reduce the environmental impacts of chemicals, the researchers said.
Source : Sky News