A new international research study is warning PFAS 'forever chemicals' are above drinking water guidelines and exceed safe limits.

A new UNSW-led international study led by the University of New South Wales, published in Nature Geoscience, assessed the levels of PFAS contamination in surface and ground water around the globe.

https://www.nature.com/articles/s41561-024-01402-8

Per-and poly-fluoroalkyl substances – commonly known as PFAS – are a group of over 14,000 human-made chemicals that have been popular since the 1950s for their diverse uses in resisting heat, water, grease and stains.

The substances have been commonly found in household products like non-stick frying pans, clothing, cosmetics, insecticides, and food packaging, as well as speciality industry products, like firefighting foam.

However, despite their broad skillset, the chemicals have a dark side: they’re known as ‘forever chemicals’ because once they’re in the environment – or bodies – they don’t degrade further.

The study has found that much of global source water exceeds PFAS safe drinking limits.

PFAS have been linked to environmental and health issues, including some cancers, but a lot remains unknown about the true scale and potential impacts of the problem – including how much is in our water supply.

“Many of our source waters are above PFAS regulatory limits,” says senior author of the study, UNSW Engineering Professor Denis O’Carroll.

“We already knew that PFAS is pervasive in the environment, but I was surprised to find out the large fraction of source waters that are above drinking water advisory recommendations,” he says.

“We're talking above 5 per cent, and it goes over 50 per cent in some cases.”

This is the first study to quantify the environmental burden of PFAS on a global scale.

The research team pulled together PFAS measurements from sources around the world, including government reports, databases, and peer-reviewed literature. Altogether, they collated more than 45,000 data points, which span roughly 20 years.

The study also found high concentrations of PFAS in Australia, with many locations above recommended drinking water levels. This tended to be in areas where firefighting foams had been used in the past, such as military institutions and fire training facilities.

Prof. O’Carroll stresses that these PFAS traces are found in source water, such as dams, and not drinking water itself – drinking water goes through treatment plants, some of which are designed to reduce the amount of chemicals such as PFAS in our water before it comes out of the tap.

However, some water providers – for example, Sydney Water – don’t routinely measure the broad range of PFAS potentially in our drinking water, says Prof. O’Carroll.

“Drinking water is largely safe, and I don't hesitate drinking it,” he says. “I also don’t suggest that bottled water is better, because it doesn’t mean that they’ve done anything differently than what comes out of the tap.

“But I certainly think that monitoring PFAS levels and making the data easily available is worthwhile.”

A contentious debate: how much PFAS is too much?

Most people in Australia – and in many places around the world – are likely to have low levels of PFAS in their bodies.

However, the potential health risks of PFAS chemicals are poorly understood and as yet have not been agreed on universally.

According to an Australian Government expert health panel, there is limited to no evidence that PFAS poses clinically significant harm to human health – although further afield, peak bodies in the US and Europe suggest that PFAS is linked to adverse health outcomes, such as lower birth weight in babies, higher levels of cholesterol, reduced kidney function, thyroid disease, altered sex hormone levels, reduced vaccine response, and liver, kidney, and testicular cancers.

In 2023, the World Health Organisation (WHO) declared PFOA, a type of PFAS, a category one human carcinogen.

The study suggests that actual PFAS pollution in global water resources could be higher than suspected.

This is, in part, due to the fact that only a limited number of the 14,000 PFAS in existence are monitored and regulated and also because the levels of PFAS in consumer products are higher than expected.

“There’s a real unknown amount of PFAS that we’re not measuring in the environment,” says Prof. O’Carroll. “Commercial products like garments and food packaging have a lot more PFAS in them than we realise.

“This means we’re likely underestimating the environmental burden posed by PFAS. ...

“We should have judicious use of some of these chemicals. Just because they’re available, doesn't mean that we should use them.”

Prof. O’Carroll and his team are now trying to develop their research by quantifying these levels of PFAS from commercial products in the environment.

They are also working to develop technologies that can degrade PFAS in drinking water systems, and looking at developing predictive models that determine where PFAS will go in the environment.

The studies will be in progress over the next two years and aim to be completed by 2026.

Click here to access the full study Underestimated burden of per- and polyfluoroalkyl substances in global surface waters and groundwaters