A group of synthetic substances known as “forever chemicals” because of their environmental persistence have been found in otters across England and Wales.
The study led by Cardiff University’s Otter Project analysed historical data and found perfluoroalkyl and polyfluoroalkyl substances (PFASs), which have been linked to health problems in both humans and wildlife, in Eurasian otters.
It concludes this suggests “widespread pollution” of British freshwaters today.
The study found most PFASs in otters were associated with wastewater treatment works or use of sewage sludge in farming, suggesting this was a “significant and concerning” route into rivers.
The Cardiff researchers said studying contaminants in otters was vital to understanding potential health risks. Their study was published just days before a parliamentary report said no English river was free from pollution.
Emily O’Rourke, a PhD student and lead author of the study, said: “PFASs are a large family of synthetic chemicals used in consumer products for their oil and water-repelling properties, in food packaging, non-stick cookware, waterproof clothing, stain resistant products, paints and fire retardants, amongst other things.
“They’re known as ‘forever chemicals’ because their strong carbon-fluorine structure means they don’t break down easily in the environment. In recent years there have been efforts to phase these chemicals out, but they remain ubiquitous because of their environmental persistence.”
Eurasian otters are top predators of British freshwaters and can act as strong indicators of the levels of these chemicals in the environment. In this study, analysis of livers from otters across England and Wales found PFASs in all 50 sampled. In more than 80%, 12 different types of PFASs were found.
The study sampled otters that died in 2007-09 and looked at where they were found, along with land use, from that time. The researchers chose this period because it coincided with changes in legislation and use of PFASs – the two most widely used were being phased out but replacements were emerging.
