Healthcare (Commonwealth Union) – A recent study by the University of New South Wales (UNSW) has uncovered at least 31 types of PFAS in the water supply of Sydney, the most populated city in Australia. This consists of 21 PFAS never before detected in Australian tap water and one identified in tap water anywhere in the world for the first time.
UNSW Sydney scientists confirmed the presence of 21 previously unrecorded PFAS compounds, raising the total detected in Sydney’s drinking water to 31.
Although official health advice currently states there is limited evidence linking PFAS exposure to human illness or significant harm, the research team says the results highlight the importance of expanding water quality monitoring.
Published today in the journal Chemosphere, the study draws attention to two newly identified PFAS compounds. One, known as 6:2 diPAP, has been found in bottled water and various consumer products but had never appeared in tap water samples. The other, 3:3 FTCA, has never before been detected in Australian tap water and has only been reported once worldwide in a drinking water source.
PFAS – short for per- and polyfluoroalkyl substances – are often referred to as “forever chemicals” because they resist natural breakdown, remaining in the environment and the human body for decades.
In a report earlier this year, it was noted that 11 genes may be a key factor in identifying the brain’s response to PFAS, which is a concern because they can cross the blood-brain barrier.
Researchers of the study stated that although they can pose potential health risks, current levels of exposure through drinking water in Australia are generally regarded as low, with national guidelines designed to minimise lifetime risk. Nevertheless, the WHO and other international and domestic health bodies continue to review and update safety assessments.
According to lead author Professor William Alexander Donald of UNSW’s School of Chemistry, PFAS levels vary depending on the water catchment, with higher concentrations typically found near suspected contamination sources.
He indicated that Sydney’s water complies with existing Australian standards, but when measured against health benchmarks used overseas, some samples were close to or above the recommended safety thresholds.
“Detecting PFAS not previously reported in tap water highlights that our monitoring programs are now uncovering more of the chemicals present in our supply.”
PFAS have seen extensive use in products such as firefighting foams, non-stick kitchenware, water-repellent fabrics, and various industrial processes. Across the word, discoveries of PFAS contamination near airports, defence sites, and landfill areas have prompted stricter regulatory measures.
In early 2024, researchers examined 32 tap water samples and 10 bottled water samples collected from Sydney’s water catchment zones. These included 10 locations in the Ryde catchment, 13 in Potts Hill, four in Prospect, and five in North Richmond. Their testing revealed the presence of PFOS – a long-lasting firefighting foam chemical and recognised carcinogen – in certain North Richmond samples, measuring 6 parts per trillion (ppt). This level is 2 ppt lower than Australia’s guideline limit of 8 ppt, yet exceeds the US EPA’s advisory threshold of 4 ppt.
Another notable result was the first documented detection in Australian drinking water of 3:3 FTCA – a short-chain degradation product derived from firefighting foams. At present, there is no established toxicity profile or regulatory benchmark for this compound in drinking water, though its occurrence is concerning due to its chemical resemblance to other PFAS known to present health hazards.
“We were also surprised by finding 6:2 diPAP,” explained Professor Donald. “This study reports the first detection of this PFAS in tap water globally.”
The scientists note that preliminary studies indicate 6:2 diPAP could impact the thyroid and reproductive systems, though they emphasise that more research is required.
