MELBOURNE, July 10 (Xinhua) -- Young birds living near contaminated industrial and military sites in Melbourne's southwest, Australia, carry especially high levels of PFAS (per- and polyfluoroalkyl substances), or "forever chemicals," a new study reveals.
The study found PFAS concentrations peaked in newly fledged birds, reflecting transfer from mothers via eggs and high exposure through insect-heavy diets during early development, according to a statement released recently by Australia's Macquarie University.
Researchers analyzed blood samples from house sparrows captured at 16 sites, including areas near a Royal Australian Air Force base, a wastewater treatment plant, and major petrochemical facilities.
PFAS are widely used synthetic chemicals known for their persistence in the environment and ability to bioaccumulate. Wildlife concentrations are highest near petrochemical plants and former firefighting training sites where PFAS-containing foams were used, said researchers from Macquarie University and the Environment Protection Authority Victoria.
"The levels of exposure we found were greater than previously measured in other sparrow populations," said the study's lead researcher Max Gillings at Macquarie University.
Median whole-blood concentrations of perfluorooctane sulfonate (PFOS), one of the best-known PFAS chemicals, were about 10 times higher than levels recorded in sparrows from uncontaminated rural sites in Norway, according to the study published in Environmental Science and Technology.
PFAS levels declined with birds' age, with juveniles and adults showing progressively lower concentrations. Researchers linked this pattern to dietary shifts, as chicks rely heavily on invertebrates such as insects and worms, a key driver for PFAS exposure.
"Similar trends in PFAS levels with age have been reported for a wide range of species, including humans and other mammals, and this seems to be linked to transfer from mother to offspring," said Gillings. ■
