The Australian Bureau of Statistics (ABS) has this week released new data which tells us about the presence of per- and polyfluoroalkyl substances (PFAS) in Australians’ bodies.
The data comes from concentrations measured in blood samples of nearly 7,000 people aged 12 and over, collected as part of the National Health Measures Survey for 2022–24.
The findings are concerning, showing PFAS are detectable in the vast majority of the Australian population, to varying levels.
But are they cause for alarm? What do these findings mean for our health?
‘Forever chemicals’
PFAS, often called “forever chemicals”, are a group of thousands of different human-made chemicals. The molecular structure of PFAS chemicals – characterised by extremely strong bonds between carbon and fluorine atoms – makes PFAS resistant to degradation.
Many PFAS products are very effective for their resistance to water, oil, grease and stains, while others promote foaming. Since the 1940s, PFAS chemicals have been widely used in many consumer and industry products, such as non-stick pans, stain-resistant fabrics and firefighting foam.
One of the downsides of PFAS is their potential to bioaccumulate, or gradually build up in the body.
Important exposure pathways include ingestion of PFAS in drinking water, in food, or absorption through the skin. Absorption of small amounts progressively builds up in the organs of people and animals, particularly the liver.
Exposure to PFAS is associated with a heightened risk of many adverse health outcomes. These include reduced fertility, and increased risk of some cancers, liver disease, kidney disease, high cholesterol and obesity.
Digging into the data
The ABS data measured 11 types of PFAS. The group of PFAS chemicals they selected reflects the most commonly detected forms from previous studies. The concentration of PFAS chemicals is measured in blood serum in nanograms per millilitre (ng/mL).
Three types of PFAS were detected in the blood of more than 85% of Australians, while the remainder were detected in lower proportions of people.
The type of PFAS most commonly detected in blood was perfluorooctanesulfonic acid (PFOS). It was found in 98.6% of samples.
PFOS accumulation has been a major problem in firefighters. Many were exposed occupationally to PFOS, sometimes for decades, and many suffered an unusually high incidence of disease, including a suspected cancer cluster.
The below graph shows the level of PFOS increases with age. This could be because it accumulates in the body over time, and because many types of PFOS are being phased out. From 2004 its use in firefighting was phased out by major users, such as the Department of Defence.
PFOS was also found to be higher in males – research shows PFAS is excreted more rapidly in females, including through menstruation and breastfeeding.
The second most commonly detected type of PFAS detected in Australian blood samples was perfluorooctanoic acid (PFOA), in 96.1% of samples. PFOA has recently been classified by the World Health Organization as a group 1 carcinogen, meaning it’s a recognised cancer-causing agent.
The third most commonly detected type of PFAS was perfluorohexane sulfonic acid (PFHxS), which was detected in 88.1% of samples.
So what are the implications?
The National Health Measures Survey identified a relationship between higher mean PFOS levels and markers of chronic disease including high total cholesterol levels, diabetes and kidney function.
However, it’s important to note this is only 7,000 people, and the data were weighted to be representative of the Australian population. There may be other factors, such as lifestyle or occupation, that have influenced the results.
While these findings may be concerning, they’re not cause for alarm. The scientific evidence more broadly doesn’t tell us conclusively whether concentrations of PFAS equivalent to those seen in the current data would have a direct effect on disease outcomes.
Some good news is that overall, this data suggests we have less PFAS in our blood compared to people in other countries.
Why this data is important
The ABS report provides the most detailed national baseline data on PFAS in the Australian population to date.
While many people are concerned about PFAS, some Australian communities have been particularly worried.
For example, in August 2024 it was revealed that a water filtration plant in the Blue Mountains contained substantial concentrations of PFAS. This was probably due to a major petrol tanker crash in 1992 and residual effects of PFAS from firefighting foam used to respond to that incident.
While people can have a blood sample taken to measure PFAS levels, it’s very expensive. NSW Health advises PFAS testing is not covered by Medicare or private health insurance.
Reports are emerging of Blue Mountains residents that have paid for blood testing getting very high concentrations of PFAS. These ABS results will help people who do receive blood testing assess how their results compare with typical results of a person of the same age and sex. People with concerns should consult a medical professional.
The ABS data will also be valuable for medical practitioners and public health authorities, providing important information to guide the management of PFAS contamination and its potential health effects.
