Concern around the extent of PFAS contamination in Australia has been raised after American activist Erin Brockovich warned the government needed to act quickly to prevent the spread of the toxic chemical.
However, information is very scarce around how many, and where, the PFAS-contaminated sites are and what the health effects of the chemical might be.
When it comes to PFAS it seems there are far more questions than answers. Let's take a look at a few:
What is PFAS?
Perfluorinated chemicals are man-made compounds and have many uses because they are resistant to heat, water and oil.
They are in hundreds of products. Some examples are carpets (to make them stain-proof) and non-stick cookware.
The chemicals also have industrial uses, including in substances like firefighting foams.
Officially they are named per- and polyfluoroalkyl substances (PFASs) and were previously referred to as perfluorinated chemicals (PFCs).
The PFAS group includes several sub-categories of chemicals but the focus in Australia is on perfluorooctane sulfonate (PFOS), perfluoro-octanoic acid (PFOA) and perfluorohexane sulfonate (PFHxS).
What are the health impacts of PFAS?
Authorities overseas, including the US Environmental Protection Agency (EPA), have found PFOA and PFOS chemicals (a type of PFAS) can cause reproductive and developmental, liver and kidney, and immunological effects in laboratory animals.
Both PFOA and PFOS have caused tumours in animals, according to the US EPA.
The EPA found increased cholesterol levels among exposed populations, with more limited findings related to:
- Low infant birth weights
- Effects on the immune system
- Cancer (for PFOA) and
- Thyroid hormone disruption (for PFOS)
According to the Department of Defence, the chemicals have been used in Australia and around the world in many common household products and specialty applications.
"As a result, most people living in developed nations have some PFAS in their body," the Defence website states.
What is Australia doing about the risk of PFAS contamination?
In 2004, Australia's Department of Defence commenced phasing out its use of legacy firefighting foam containing PFOS and PFOA as active ingredients and transitioned to a more environmentally safe product.
"The release of PFAS into the environment has become a concern because we've learned these chemicals can persist in humans, animals and the environment," the department stated on its website.
A study commissioned by the Federal Department of Health is currently underway by the Australian National University (ANU).
It is looking at the health impacts on people who have come into contact with the chemical from defences bases in three locations including Oakey in Queensland, Katherine in the Northern Territory and Williamtown in New South Wales.
ANU Professor Martyn Kirk said his team of researchers are looking at four different strands of enquiries including social and health impacts.
"The first part was to actually conduct focus groups and to understand the experience of people living in these towns because actually these chemicals have resulted in a lot of social effects and people have been very stressed and anxious about it," Professor Kirk said.
"The second part is a blood-testing program, which is piggy-backing on a program that the Federal Government ran, testing people's blood for PFAS and in that there are over 2,500 people who have submitted blood [samples] to us.
"Thirdly, there's a survey which we're just about to release in those towns where we'll be asking people to tell us about their exposures and also the health effects that they believe they've experienced.
"Then lastly, there is a data-linkage study where we're going to be linking data on people who have ever lived in these towns and rates of cancers and other diseases and look at whether the rates are higher in those towns compared to towns that don't have PFAS contamination."
It comes off the back of the findings from an expert health panel set up to advise the Australian Government on the scientific evidence about potential health impacts from PFAS exposure, released in 2018.
It reviewed 20 recently published local and international reports and found "fairly consistent reports with several health effects" including:
- Increased levels of cholesterol
- Increased levels of uric acid in the blood
- Reduced kidney function
- Alterations in some indicators of immune response
- Altered levels of thyroid hormones and sex hormones
- Later age for starting menstruation and early menopause
- Lower birth rate of babies
But the panel concluded there was no current evidence that suggests an increase in overall cancer risk to PFAS exposure and that "the level of health effect reported in people with the highest exposure is generally still within the normal ranges for the whole population".
What are other countries doing about PFAS?
The United States EPA says certain PFAS chemicals are no longer manufactured in the US after eight major chemical manufacturers agreed to eliminate the use of PFOA and PFOA-related chemicals in their products and as emissions from their facilities.
Although PFOA and PFOS are no longer manufactured in the United States, they are still produced internationally and can be imported into the United States in consumer goods such as carpet, leather and apparel, textiles, paper and packaging, coatings, rubber and plastics.
Where are the PFAS-contaminated sites?
ABC News has obtained a list of more than 60 locations in Queensland alone that have been identified by authorities as being contaminated by the synthetic compounds.
A spokesman for the Department of Environment and Science (DES) said potential PFAS contamination is monitored by a number of government agencies.
It is unclear how many other sites exist nationally.