New guidelines for Australia's drinking water are set to target potential cancer-causing chemicals known as PFAS (per-and poly-fluoroalkyl substances).
The National Health and Medical Research Council (NHMRC) has released draft guidelines that will propose much lower limits for four types of PFAS than were included in the last guidelines, published in 2018.
High levels of PFAS, otherwise known as 'forever chemicals', have been discovered in groundwater across Australia, with one study from the University of New South Wales published earlier this year describing Australia as a "hotspot" for the substances.
The NHMRC guidelines are now open to public consultation, with the final guidelines due for publication in April 2025.
What are PFAS?
PFAS is the short name for a family of manufactured chemicals used in industry and consumer products since the 1940s.
There are more than 4000 types of per- and poly-fluoroalkyl substances (PFAS) that are valued for their heat, water and stain-repelling properties.
They are in a vast range of products including food packaging, make-up, paint, carpet, and in previous decades, certain types of firefighting foams.
Why are PFAS chemicals problematic?
PFAS are sometimes branded as forever chemicals because they are long-lived and don't easily break down.
A World Health Organization agency has classified PFOA as carcinogenic to humans and PFOS as possibly carcinogenic.
Experts say they are ubiquitous, meaning they are found everywhere on earth in air, soil, water and our bodies.
How to PFAS affect humans?
Scientists suspect PFAS might pose broad health risks including cancer, but research is inconclusive.
The US Environmental Protection Agency cites peer-reviewed scientific studies showing exposure to certain levels of PFAS could lead to increased risk of prostate, kidney and testicular cancers
The EU says PFAS can lead to liver damage, thyroid disease, obesity, fertility issues and cancer.
Australians generally have at least three types of PFAS in their bodies: PFOS, PFOA and PFHxS.
What are the new proposed guidelines?
- PFOS reduced from 70 nanograms per litre to 4ng/L
- FOA reduced from 560ng/L to 200ng/L
- New limits for PFHxS (30ng/L) and PFBS (1000ng/L)
- No health-based guideline value proposed for GenX chemicals, which are restricted in the US and Europe
Why are Australia's PFAS guidelines different than in other countries?
The proposed drinking water guidelines are less stringent than the European Union, the US and Canada.
Australia placed less emphasis on human studies of PFAS effects, compared to the US, over quality concerns.
Officials say the new marks still err on the side of caution and are based on comprehensive evaluations of the latest evidence.
Should you be concerned about PFAS in drinking water?
RMIT chemistry professor Oliver Jones said the presence of PFAS in water does not necessarily mean the water is toxic or enough to cause harm.
"The dose makes the poison, everything is toxic at the right amount, even water," he said.
"For example, we know you can get skin cancer from too much sun, but that doesn’t mean you will get cancer as soon as you step outside."
Jones believes Australian drinking water does not contain dangerously high levels of PFAS.
"While some PFAS have been linked to health effects, the concentrations needed to cause such effects are much, much higher than the levels typically found in Australian drinking waters," Jones said.
"In addition to that, we aren’t sure if the major source of PFAS exposure to most people is water."
NSW Chief Medical Officer Kerry Chant reassured people the risks are low, and warned against getting a blood test for PFAS
"PFAS is a ubiquitous chemical, and we do not really know how to interpret tests - as a general rule, we don't test what we don't know how to interpret."
