‘Forever chemicals’ found in platypuses sparks warning for people in NSW

An Australian-first study has found the toxic “forever chemical” PFOS in platypuses, sparking warnings people in New South Wales may be more exposed than once thought.

Scientists from Western Sydney University (WSU) have discovered perfluorooctane sulfonate (PFOS) in the livers of eight deceased platypuses collected from numerous eastern NSW rivers, from the north coast in Bellingen to the Alps of Jindabyne.

The near-threatened monotremes were mostly collected from areas that are not known PFOS hotspots, fuelling concerns the chemicals are far more prevalent in Australia’s environment than previously understood.

Lead researcher and PhD candidate Katherine Warwick said the findings “shocked” her, considering the animals came from areas ranging from remote to urban, meaning there is pollution in those environments.

“What that’s telling us is PFOS contamination is much more widespread than what we know.”

It is the first study of its kind on platypus and sheds light on yet another threat to a species already vulnerable to impacts associated with human activity.

The study reveals the Australian monotremes have PFOS levels similar to those found in river otters and lower than those in American mink, both of which live in similar freshwater environments.

WSU associate professor Dr Ian Wright said Americans use the mink and the river otter as sentinels.

“There is a growing literature from lab studies showing that there’s an absolute host of medical issues and disease that this can cause as the concentrations build up,” he said.

Numerous studies have found PFOS are toxic to humans and can have harmful health effects such as liver and thyroid diseases, and are linked to some cancers.

They are still found in everyday products such as non-stick pans and makeup.

Hotspots in Australia tend to be around Royal Australian Air Force (RAAF) bases where firefighting foam that contained the man-made chemical was widely used.

They leach from such products into water systems, causing contamination.

Because of their widespread use, they are found in the blood of people and animals across the world.

Species from Hunter River worst affected

All eight wild platypuses collected from NSW waterways over the past two-and-a-half years returned results with concentrations of some PFOS in them, ranging from 4 micrograms per kilogram (µg/kg) to 1,200 µg/kg — some of the highest concentrations of any species in the world.

The study said there were currently no concentrations considered safe for platypus health, “however, draft guidelines by the Australian government suggest that exposure directly from their diet should not exceed 3.1 µg/kg of wet weight.”

The researchers did not choose the sites where the animals came from and were sent the carcasses by members of the public.

The worst- ffected was found in the Hunter River in Morpeth, in the state’s Hunter region.

One platypus from the Ourimbah Creek on the Central Coast returned the second-highest results of 740 µg/kg.

That was followed by one from the Wingecaribee River at Berrima, at the top of Sydney’s drinking water catchment, with a PFOS liver concentration of 390 µg/kg.

The ninth platypus tested was the only one that virtually had none of the man-made chemical present in its liver.

It was living in filtered water in captivity at Sydney’s Taronga Zoo.

As this latest study suggests, PFOS bioaccumulates, meaning organisms take in more of the chemicals than they excrete.

The research suggests the platypuses are consuming the chemicals through their diet, and through sediment on the bottom of the creeks and rivers whilst consuming macroinvertebrates or water bugs that may also be contaminated.

They found the larger the platypuses’ tails — an indication of fat and health — the higher the concentrations of PFOS.

Dr Wright said people may have more “skin in the game” than they think.

“It could be in our drinking water, it could be in the food we eat, it could be in the crops we grow,” Dr Wright said.

Platypuses are an apex predator in the food chain.

They are a sentinel species, meaning research on them can also provide insights for how environmental factors may affect humans.

“They’re known as the forever chemicals, and they haunt the environment and many aspects of biodiversity, but they also kind of potentially haunt us as well,” he said of PFOS.

It is not clear what the source of the chemicals were in those waterways the platypus came from.

“Following on from America, we’ve got a pretty good idea that it could come from things like treated sewerage, from landfill, from industrial discharges,” Dr Wright said.

Need to be ‘discussing ways to improve this’

Lead researcher Ms Warwick said one of the main things this work shed light on was that the “most unique species in the world” was extremely understudied.

“If we’re finding PFOS in their livers, then what else are they accumulating? And what is the impact that this is having on their abundance and distribution within New South Wales?” she asked.

“For this to be happening, I think, puts a lot of pressure on governments and managing bodies to actually be looking into this issue, and then to be discussing ways that we can improve this.”

All of the mammals they tested died of other causes, such as drowning from fishing gear and vehicle trauma, so it is not clear what impact the PFOS had on the health of the platypus.

“This is one of the big question marks that we have,” Ms Warwick said.

The next step, she said, was to find out what impacts the chemicals were having on the platypus and what that meant for their long-term survivability.

The researchers want governments to do more to clean up the “forever chemicals” from the state’s waterways.

“I don’t think we treat our rivers with the respect they deserve,” Dr Wright said.

“We really need to take every measure possible to keep out pollutants.”