UK's inland bathing sites tainted by chemical pollutants and antibiotic resistant genes, researchers find

Editors' notes

This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility:

fact-checked

trusted source

proofread

The U.K.'s rivers are contaminated with a mixture of chemical pollutants and antibiotic resistant genes, which could be causing severe harm to people and aquatic species, according to the findings of a new study.

The University of York study found sites popular with swimmers around the U.K. to be suffering from pollution with bacteria and chemicals alongside resistant genes that could limit the effectiveness of modern medicine.

Researchers worked with Surfers Against Sewage, Watershed Investigations and a range of community groups across the U.K. They discovered designated inland bathing sites in the U.K. are polluted with a cocktail of pollutants including pharmaceuticals, pesticides, personal care products, chemicals produced from burning fuel and antimicrobial resistance genes.

International analysis

As part of the study, 23 river and lake bathing waters across England, Wales and Scotland were sampled twice a day for one week in the summer. Samples were then shipped to the laboratories in York where they were analyzed for about 100 chemical pollutants and to Helsinki for analysis for a range of antimicrobial resistance genes.

Chemical pollutants were detected at all of the bathing sites monitored. The highest numbers of chemicals (48 chemicals of the 100 monitored for) were found in samples taken from the River Nidd at Knaresborough, Yorkshire and the Sheep's Green on the River Cam in Cambridge. Sheep's Green was also the site with the highest level of chemical pollutants.

Detected pollutants

Four chemicals, caffeine, nicotine, metformin (a type 2 diabetes medicine), metconazole (a pesticide) and lincomycin (an antibiotic) were detected at all 23 bathing sites. The banned forever chemical PFOA, which has been associated with cancers and thought to affect the immune system and reproduction, was found in 95% of samples.

Other commonly detected pollutants included antihistamines, antidepressants, insecticides, UV filters used in sunscreens and polycyclic aromatic hydrocarbons, most likely arising from vehicle emissions.

Concerning impacts

While the levels of chemicals were low and very unlikely to cause health impacts in the short term, some of the chemicals are known to cause impacts in the longer term from prolonged exposure, which is more concerning.

With the exception of the River Teme in Ludlow, antimicrobial resistance genes (genes that can make microbes resistant to medical treatments) were detected across all of the monitored sites. The largest number of genes (53 of the 71 looked for) was seen in a sample from the River Dart in Devon. The genes seen at some of the bathing sites included those that code for resistance to last resort antibiotics (i.e., those that are reserved for use when more commonly used antibiotics are ineffective at treating an infection).

Unique research

Professor Alistair Boxall, from the University of York's Department of Environment and Geography explained, "Most work on bathing water contamination in the U.K. has focused on bacterial pollution. This study is unique as it explores a much wider range of pollutant classes. Many of the chemical pollutants occur all the time in our rivers even when bacterial levels are low. The current monitoring by regulatory agencies in the U.K. won't protect swimmers from the chemical exposure."

The results of the study highlight the need to expand the current regulatory monitoring approaches to include a broader range of pollutants that may pose risks to human health.

Discover the latest in science, tech, and space with over 100,000 subscribers who rely on Phys.org for daily insights. Sign up for our free newsletter and get updates on breakthroughs, innovations, and research that matter—daily or weekly.

Subscribe

Informing policy

The findings of the study are set to inform future water quality policies and shape the direction of environmental regulations in the U.K. A government consultation on Bathing Water Regulation reform in England and Wales is welcoming responses until Monday 23 December.

Professor Boxall added, "We have shown yet again that our rivers are contaminated with a mixture of chemical pollutants, some of which could be causing harm to aquatic species and to humans. We really should be doing better. It is a perfect storm—these sites are polluted with bacteria and chemicals that can make people sick as well as resistance genes that could limit the effectiveness of medical treatments.

Reducing emissions

"One potential solution is for the U.K. Government to adopt some of the changes in the updated EU Urban Wastewater Treatment Directive. This would reduce the emissions of many of the chemical pollutants we detected. It will also introduce tighter controls on smaller wastewater treatment works which are flowing under the radar at the moment and require monitoring of resistance gene emissions from large treatment works."

Dr. John Wilkinson, who co-led the study said, "These findings are not surprising. We know that UK rivers are polluted with a diverse range of chemicals used in the household, farming and even from our use of medicines."

He added, "This study also shows the power of citizen science for monitoring freshwaters, an area where York is leading the way."

Giles Bristow, chief executive of Surfers Against Sewage, said, "The saturation of our waterways with sewage pollution is well known, but these findings demonstrate there's a lot more than human waste lurking beneath the surface. With regulators and the government turning a blind eye, citizen scientists have acted to lift the lid on the toxic chemical cocktail that's leaching into our rivers, lakes and seas."

Urgent reform

"The true environmental and health impact of this slurry of pollutants, which include banned and carcinogenic forever chemicals, are still being revealed. Yet the government is allowing them to swamp the wild waters where we surf and swim, and where fragile ecosystems are already on the brink of collapse. Bathing regulations urgently need wholesale reform and the government's consultation, which is open right now, must deliver.

"These findings must be the catalyst that ends the era of inadequate water quality testing and kick-starts a future where the public are given a full picture of what's coursing through the U.K.'s waters. We've lifted the lid, now it's time to flush the pollutants out of our rivers, lakes and seas."

Provided by University of York