Cocktail of chemicals found in River Cam in Cambridge

A cocktail of chemicals was found in the River Cam in Cambridge during a nationwide study of bathing water quality.

Watershed Investigations used volunteers, including from Cam Valley Forum, to test 23 rivers and lakes used for swimming, twice a day, every day for a week.

Designated Bathing Water sites are monitored by the Environment Agency weekly during the bathing season, but testing focuses on two faecal bacterial indicators only, E. coli and intestinal enterococci.

Watershed’s testing also looked for other pollutants including pharmaceuticals, PFAS, pesticides, vet medicines, caffeine and nicotine.

The study found the River Cam to have the joint highest number (48) of pharmaceuticals, pesticides, metals and industrial chemicals.

The top three organic pollutants found in the River Cam were paracetamol, caffeine and chrysene. Chrysene can originate from various sources, including road runoff and as a combustion product, as well as a component found in the banned preservative, creosote.

A spokesperson for Cam Valley Forum said: “We are not surprised to see the high trace organic concentrations in the Cam at Sheep’s Green. There are more than 30 sewage treatment works (STWs) upstream of Sheep’s Green and some of these Anglian Water assets are in need of upgrades.

“There is a combined population equivalent for these STWs greater than 105,000 which is two-thirds the population of Cambridge. The effluent from STWs serving such a large population will inevitably contain pharmaceuticals.

“The situation is worsened in the Cam valley because over-abstraction of water by Cambridge Water company and others, which has resulted in reduced river flows and insufficient dilution of STW effluents. As a result of this combination of problems, CVF is very concerned for the health of life in our precious chalk streams.”

While the chemicals were not found at concentrations high enough to impact human health, scientists are still concerned about what happens when those chemicals get combined. It is unknown what the effects of a mixture could be on humans or wildlife.

The spokesperson added: “The concentration of paracetamol and caffeine is incredibly low. For example, you’d need to drink a small swimming pool’s worth of river water to get the same hit of caffeine as from a cup of coffee. However, we are more concerned by the levels of the chemical chrysene. The research shows that it was present in the Cam this summer at eight times the Dutch government’s Maximum Acceptable Concentration.

“The EU warns that this substance may cause cancer and that it is very toxic to aquatic life, with long-lasting effects. We need this to be investigated to identify the source.”

The study was a collaboration with Surfers Against Sewage, Watershed Investigations and the University of York to raise awareness about the quality of inland bathing waters and demand radical reform of current legislation to account for emerging pollutants that pose new threats to public health.

The Environment Agency said it will “continue to work closely with the agriculture sector, water companies and local communities to understand how pharmaceutical compounds enter our water environment and to ensure the highest standard of bathing waters for the public”.

Giles Bristow, chief executive of Surfers Against Sewage, whose volunteers helped collect data samples for the study, said the results show how important it is for the government to commit to more extensive testing.

“The true environmental and health impact of this slurry of pollutants, which include banned and carcinogenic forever chemicals, are still being revealed and yet 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,” he said.

“Bathing regulations urgently need wholesale reform and the government’s consultation, that’s open right now, must deliver.

“These findings must be the catalyst that closes 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 UK’s waters.”

The findings will inform water quality policies and shape the direction of environmental regulations, with a government consultation on Bathing Water Regulation reform in England and Wales, accepting responses until Monday (23 December).