New research finds toxic ‘forever chemicals’ in otters across Wales and England

A new study led by Cardiff University suggests the presence of ‘forever chemicals’ in the otter population indicates widespread pollution of UK rivers.

The study led by Cardiff University’s Otter Project was carried out in collaboration with the Centre for Environment, Fisheries and Aquaculture Science and the UK Centre for Ecology and Hydrology.

Analysis of historical data collected from Eurasian otters revealed perfluoroalkyl and polyfluoroalkyl substances (PFASs), which have been linked to health problems in both humans and wildlife

PFASs are a group of synthetic substances known as “forever chemicals” because their structures mean they do not break down quickly or easily.

Eurasian otters are top predators of British freshwaters and are good indicators of the levels of these chemicals in the environment, offering vital understanding of potential health risks.

The study took a sample of otters across England and Wales that died during 2007-09 and analysed their livers. The results revealed PFASs in all 50 sampled, and 12 different types of PFASs were found in more than 80% of the samples.

Significant and concerning

The study findings were backed up when further samples were collected in 2015-18 in a separate study and again found PFASs in otters and other wildlife,

As many of the otters with PFASs were found to be associated with outlets from wastewater treatment works, sewage and farming land, the study suggests that these are “significant and concerning” route into rivers.

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.

“Further work is needed to understand where the highest concentrations are now and any current sources of contaminants.

“It is deeply concerning PFASs were introduced into the environment through industrial and farming practises – policy and management action is vital to address this where it remains an issue.

“Our study provides further evidence to support the conclusion of the recent Environmental Audit Committee’s report which highlighted a ‘chemical cocktail’ of contaminants in our waterways.

“The report recommended an independent evaluation of the risks to human health and the environment of spreading sewage sludge – our study provides important evidence that PFASs should be included in that evaluation.”

Important resource

Dr Elizabeth Chadwick, Principal Investigator on the Otter Project, said: “Our research was possible though the ongoing collection of otters found dead from across Britain.

“Our archive has samples from more 4,000 individuals collected since 1992; it is a unique and important resource for understanding this protected species, and for understanding environmental contamination and health.

“By studying chemical contaminants found in otters we can understand the relative levels in the environment and the potential health risks to both wildlife and humans.

“We encourage the public to continue reporting otters found dead so that our research can continue.”

Information on Cardiff University Otter Project, and how to report dead otters, can be found on the project website.