Many Australians have some level of PFAS — often dubbed forever chemicals — in their body, but understanding their impacts and strategies for reducing them is lacking.
This week, scientists and experts continued to give evidence to a federal inquiry investigating the regulation and management of per- and poly-fluoroalkyl substances, or PFAS.
Their remarks highlighted a series of knowledge gaps that make it difficult to ascertain the health impacts of these chemicals, which are present in our environment and bodies.
It also served as a reminder about one of the only known ways to reduce our levels.
What are PFAS, and how common are they?
PFAS are synthetic compounds found in a variety of industrial and consumer products, including makeup, non-stick cooking surfaces and food packaging, due to their heat, stain, grease and water-resistant properties.
They have even been found across water filtration plants, with high contamination levels in Warragamba, North Richmond and the Cascade Dam in the NSW Blue Mountains region.
They often don't degrade in the environment and build up in our bodies, earning them the title "forever chemicals".
Professor Peter Sly, deputy director of the Queensland Children's Medical Research Institute, said control groups with no level of PFAS simply "don't exist anymore".
"I'm afraid every person in Australia has PFAS levels in their body. It's a matter of how high they are," he told the PFAS committee hearing on Tuesday.
PFAS are a group of chemicals that can be added to household products to make them heat, stain, grease or water resistant. Source: SBS News
It detected three types of PFAS in the blood of over 85 per cent of the population.
While research groups currently test for over 40 different types of PFAS, the ABS estimates there are more than 15,000 identified compounds belonging to the PFAS class of chemicals.
How to reduce your PFAS levels
In 2022, a world-first Australian study investigated whether blood and plasma donations could remediate elevated PFAS levels in 285 firefighters.
Historically, firefighters have been exposed to higher levels of PFAS through the frequent use of firefighting foams, although alternatives have since been developed that do not include these chemicals.
Following 12 months of testing staff, the study found that those who donated blood every 12 weeks had a 10 per cent reduction in PFAS chemicals.
The group that donated plasma every six weeks had their PFAS levels reduced by 30 per cent, with no significant change for the control group who did neither.
Miri Forbes, one of the study authors and an associate professor at Sydney's Macquarie University, said understanding the impact of the reduced levels on the human body requires further study.
"We don't know yet. This is the first study that has found how we can reduce PFAS," she told SBS News.
"It was really exciting to know that it's possible to be able to reduce the levels of PFAS we can measure in the blood, but we need to understand, what are the health implications of that?"
Other observational studies have found women have reduced levels. PFAS leave the body during menstruation and the replenished blood supply doesn't have PFAS, lowering the overall levels.
What don't we know about PFAS?
Martyn Kirk, a professor of epidemiology at the Australian National University, told SBS News that there is still plenty we don't know about PFAS.
These blind spots include;
- The long-term health impacts of low exposure
- The health impacts on highly exposed individuals
- Where exposure comes from in the household environment
- Methods of reducing PFAS
While there have been studies that have linked higher levels of PFAS with health impacts, such as higher levels of cholesterol, many don't yield consistent results, making conclusions difficult.
Kirk said longitudinal studies, which can be reproduced and repeated, are needed to capture exposure levels across different areas and ages as well as demonstrate where levels decline over time.
He believes highly exposed people, such as firefighters, present an opportunity to understand the link to different health outcomes.
"You've got a much greater chance of being able to identify the potential relationship between exposure and disease, whereas in the community, the levels are often very low," he said.
A barrier to obtaining datasets for scientific research is the cost of samples, which are complex to interpret and expensive as a result.
Sly suggested a biomonitoring program by collecting leftover blood from hospitals and pooling samples.
"By pooling samples, you protect individuals' identity, and secondly, you only have to measure one sample rather than ten or 100," he told the PFAS committee on Tuesday.
"And you can get levels across the population," he said, adding that a similar method was currently used to test wastewater for drugs.
Should we be concerned?
Companies started phasing out PFAS in the late 1990s and early 2000s, leading to a drop in exposure and blood levels as a result, said Kirk.
"We've seen declines in the levels of PFAS in people's blood since 2000," he said.
"So we've had nearly a 10-fold decrease in the levels of PFAS in the blood of Australians, and that continues to decrease."
He said that unless you're working in one of the industries that are highly exposed, you probably don't have levels that are of concern.
However, he noted anxiety in specific communities like at Wreck Bay on the NSW south coast, where an Aboriginal community believe a "cancer cluster" is due to PFAS contamination caused by the Department of Defence.
"I think we do need to understand better to assist those communities and also provide better information for the wider community and government to make good policy."
