Baby birds show highest levels of forever chemicals
Bird populations in one city’s industrialized western suburbs have increased levels of the infamous PFAS, also known as persistent chemicals, in their systems.
Levels of these persistent chemicals were 10 times higher in some birds than in a similar study of rural birds.
The rates were highest in young birds, which pass the chemicals from their mothers and then leave the nest to feed on insects, spiders, snails and worms.
The Macquarie University-led study, published on Thursday, sampled invasive house sparrows from 16 locations in Melbourne’s south-west, including Williams Laverton Royal Australian Air Force base and the Qenos Chemical Plant in Altona.
The areas were already known to have high levels of PFAS, particularly at the still-active air force base where extensive firefighting training had taken place in the past.
Banned perfluorinated aqueous film-forming foams used to extinguish liquid fires are the primary source of PFAS in the environment globally.
In encouraging news, lead researcher Max Gillings said the results did not show that the chemicals were widely released from these contaminated areas into the surrounding environment indefinitely.
“The levels we found in the birds were not very extreme, but they were certainly higher than you would expect, for example, in a rural area,” he told AAP.
“Certainly this area of Melbourne has many potential industrial sources of PFAS pollution and that’s what’s contributing to the high levels we’re seeing.”
PFAS has been linked to developmental problems in birds, and the highest levels of the chemical were detected in the early life stages of birds, raising concerns.
“Some previous studies have certainly shown reproductive effects, so things like egg failures,” Dr Gillings said.
“We don’t know the full impact of this on their health, especially in the long term.”
The reason exposure decreases as birds get older is because more than 90 percent of their diet consists of invertebrates such as insects as nesting chicks, dropping to less than 10 percent in adults that feed mostly on grains.
However, once adults begin breeding, their diet shifts again to animal food sources to meet the energy demands of breeding and raising chicks.
“Similar trends in PFAS levels with age have been reported for a wide range of species, including humans and other mammals, and appear to be linked to transmission from mother to offspring,” Dr Gillings said.
“Our study adds further evidence confirming that PFAS pollution is a significant problem across Australia and has impacts on both communities and ecosystems.”
