High PFAS Concentrations Found in Young Sparrows in Melbourne's South-West

Scientists say they have found especially high concentrations of PFAS chemicals in young sparrows in Melbourne's south-west.

A team from Macquarie University and Environment Protection Authority analysed blood samples taken from house sparrows at 16 locations that were known to be previously contaminated with PFAS.

Sites included the RAAF Williams–Laverton base at Williams Landing, the Altona Wastewater Treatment Plant, and a chemical plant and oil refinery in Altona.

All sites were known to have had previous PFAS contaminations.

The study published today in the journal Environmental Science and Technology revealed the average level of the PFAS chemical perfluorooctane sulfonate in the young sparrows was 10 times that of birds in an uncontaminated rural site in Norway.

Lead author Max Gillings said while the levels were not as bad as the team was expecting for known contamination sites, they were several times higher than sparrow populations in other parts of the city.

He said the worst site was RAAF Williams–Laverton.

"We did find highly elevated levels of PFAS in the blood of those birds," Dr Gillings said.

"Part of it has now been rehabilitated and redeveloped into the suburb of Williams Landing, so a lot of our sampling was actually in that suburb."

Dr Gillings said the base had previously been used as a large air force firefighting training facility and the birds were mostly feeding on insects inside the restricted defence land.

He said the study did not find any strong evidence of significant off-site contamination.

"The Department of Defence has been aware of the PFAS issue at this site for quite a long time," he said.

"Prior to actually developing Williams Landing, they did conduct quite an extensive rehabilitation of the contaminated areas that they were converting into these residential environments.

"What our data does tell us is, certainly is that if sparrows are feeding from areas on these bases — so, private military areas, essentially — that there still is legacy contamination in those areas."

The Department of Defence has a dedicated web page on the management of PFAS at RAAF Williams–Laverton as well as its Point Cook base.

It said Defence investigations had found that PFAS contamination had spread through the suburb of Williams Landing due to redevelopment activities and that eating homegrown fruit and vegetables on former Defence land had been identified as a potential elevated risk.

But in a statement, a department spokesperson said there was minimal risk to residents.

"As part of the investigations, Defence conducted a Human Health Risk Assessment for RAAF Williams–Laverton which found the PFAS exposure risk to human health is low," the spokesperson said.

"Further risk assessments and environmental studies are underway.

"Defence's priority remains to support communities impacted by PFAS contamination on and around Defence sites, by reducing their exposure to PFAS through Defence's remediation program."

PFAS passed onto chicks before they hatch

PFAS (per- and polyfluoroalkyl substances) are a group of more than 14,000 synthetic chemicals used in firefighting foams, pesticides, building materials and electronics, among other uses.

They are referred to as "forever chemicals" due to their resistance to decay.

They are also known to build up in organisms in the food chains, a process known as bioaccumulation.

Dr Gillings said the team found the chemicals were being transferred from mothers into their eggs and then from the insects that the young, newly fledged birds were fed while being reared.

"Birds are in contact with the sources in the environment where PFAS tends to accumulate, so that's things like soil and dust but also through the ingestion of insects and water as well."

"The reason we focused on house sparrows is that they have quite a confined home range, so they don't move very far from their nesting site … so it gives us a really good indication of kind of localised levels of that contaminant."

He said the team had been recapturing and testing the birds and finding that their PFAS levels were generally falling as they aged.

But Dr Gillings said there was evidence to show that the early exposure was having physiological and genetic implications.

"Egg failure rates are associated with high levels of PFAS, so you'll have more eggs failing during the breeding season.

"In terms of the long-term effects, though, we're not actually sure what the overall implications are for things like reproduction and development."

The Environment Protection Authority (EPA) said the study provided valuable new evidence about the way PFAS moved through urban land-based ecosystems.

Deputy chief environmental scientist Caroline Martino said the report would strengthen the EPA's understanding of PFAS and improve ecological risk assessments.

"It is one of the first Australian studies to clearly demonstrate PFAS movement through a terrestrial food web in an urban environment, including transfer from adult birds to their offspring and through diet," she said.

"The findings are consistent with our existing understanding that PFAS can persist and accumulate near known source areas, and the patterns reported in young sparrows align with findings from international wildlife studies."

Last year, Ellis Mackay was part of a team from the University of Melbourne's veterinary school that studied PFAS levels in possums in Melbourne.

After analysing 46 common brushtail and ringtail possums found dead from illness or injury in the city, they detected PFAS in every liver sample.

The team concluded local possums were some of the most contaminated small terrestrial mammals that had been tested anywhere in the would.

Ms Mackay said she was not surprised by Macquarie University's findings.

"Unfortunately, no."

"Elevated PFAS levels have been documented in a range of wildlife species across the Melbourne region, including black swans at Albert Park Lake, dolphins in Port Phillip Bay, and ringtail and brushtail possums from across the city."

She said urban wildlife species act like environmental sentinels, revealing issues in the local environment.

"Although PFAS contamination is now ubiquitous around the world, this research led by Dr Gillings is quite concerning.

"The overall PFAS levels observed are quite high, especially from the Williams–Laverton air force base site, and the finding of elevated PFAS in fledgling birds is a particular worry as it could potentially have a range of impacts during a vulnerable stage of development."

Ms Mackay said the identification and management of any current PFAS sources must be prioritised.