Toxic 'forever chemicals' found in British, Welsh otters: study

Toxic compounds known as "forever chemicals" are plaguing not only humans, but also Eurasian otters across England and Wales, a recent study has found.

The study, led by Cardiff University's Otter Project, identified per- and polyfluoroalkyl substances (PFAS) in all 50 otters they sampled - findings they said suggest "widespread pollution" of British freshwaters.

As top predators in these waterways, otters serve as strong indicators of chemical contamination in the environment, according to the authors.

The contaminants in question - PFAS - are most notorious for their presence in firefighting foam, but they are also key ingredients in a variety of household products and in industrial discharge. There are thousands of types of these toxic compounds, which are linked in humans to illnesses like kidney and thyroid disease.

"They're known as 'forever chemicals' because their strong carbon-fluorine structure means they don't break down easily in the environment," the study's lead author, Emily O'Rourke, a PhD student, said in a statement.

"In recent years there have been efforts to phase these chemicals out, but they remain ubiquitous because of their environmental persistence," she added.

The researchers analyzed the livers of otters that died between 2007-2009, a period that coincided with changes in legislation and the use of PFAS in Great Britain, a news release accompanying the study said. While the two most widely used types of PFAS were being phased out at the time, replacements were emerging, the authors said.

In more than 80 percent of the 50 otters sampled, 12 different types of PFAS were found, according to the researchers. The authors determined that most PFAS in otters were linked to wastewater treatment works or the use of sewage sludge in farming, which they deemed a "significant and concerning" route into rivers.

The study, published by the American Chemical Society's Environmental Science & Technology journal earlier this month, was released just days before a British parliamentary report indicated that no English river was free from pollution, the authors noted.

The authors found that higher concentrations of one common type of PFAS, called PFOA, were associated with proximity to a particular factory on England's northwest coast, where that compound had been used in manufacturing processes.

"It is deeply concerning PFAS were introduced into the environment through industrial and farming practices - policy and management action is vital to address this where it remains an issue," O'Rourke said.

Altogether, Cardiff University's Otter Project has archived samples from more than 4,000 individual otters since 1992 - creating a vital resource for not only researching this protected species, but also for understanding broader environmental contamination and health issues, according to principal investigator Elizabeth Chadwick.

"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," Chadwick said in a statement. "We encourage the public to continue reporting otters found dead so that our research can continue."