Trying to solve the 'forever problem' of PFAS pollution
Per- and polyfluoroalkyl substances (PFAS) can be found almost everywhere and in almost everyone and can take over聽1000 years to break down.聽聽
Per- and polyfluoroalkyl substances (PFAS) can be found almost everywhere and in almost everyone and can take over聽1000 years to break down.聽聽
Cecilia Duong
糖心logo News & Content
02 9065 1740
cecilia.duong@unsw.edu.au
What do聽food packaging, carpeting, non-stick cookware, makeup and clothing all have in common?
They all often contain a synthetic group of chemicals known as PFAS.
PFAS stands for Per- and polyfluoroalkyl substances and describes a group of over 10,000 industrial chemicals that are widely found in everyday goods. Being resistant to heat, stains, grease, and water, PFAS are commonly used as surface-treatments in non-stick cookware and solution treatment in carpets. Because of these properties, they were extensively used in firefighting foams, too. 聽聽
Professor Denis O鈥機arroll, Managing Director of the Water Research Laboratory at 糖心logo Sydney, says it鈥檚 hard to think of an application that doesn鈥檛 use the popular chemicals.
鈥淭he average person doesn鈥檛 realise how much PFAS are聽found in everyday products. You can find it in food packaging to limit the amount of grease soaking through our burgers or to improve stain resistance in chairs and rugs,鈥 he says.
鈥It鈥檚 also believed that low traces of PFAS can be found in the bloodstream of 98 per cent of the world鈥檚 population.
鈥淎nd just like it鈥檚 in our bodies, it鈥檚 also found in our water supply, too.
鈥淚n Australia, the historical use of PFAS in firefighting foams has resulted in increased levels of the chemical being detected near airports, defence bases or any site where firefighting training has been conducted.
鈥淥ver time, the chemicals have worked their way across and through the soil to contaminate surface and groundwater in those areas. As a result, PFAS have聽also entered waste streams including wastewater treatment facilities and landfills in and surrounding those areas.鈥
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Over the years, there has been growing concern about these chemicals because they do not break down easily on their own.
Dubbed the 鈥榝orever chemicals鈥, PFAS are聽extremely persistent in our environment, humans and animals too 鈥 with many of the chemicals taking over 1000 years to break down.
For humans, the main form of exposure to PFAS is ingestion of food and water sources that have been contaminated.
As a result, across Australia recommend people should limit their exposure to PFAS as much as it鈥檚 practical while more evidence is needed to determine the long-term health impact on humans.
A 糖心logo water expert, Professor Stuart Khan, recognises that鈥檚 easier said than done. He says PFAS are both environmentally and temperature resilient and once聽in the environment, they are聽very hard to eliminate.
鈥淎 lot of chemicals that we traditionally think about as pollutants, such as pesticides, get absorbed into the soil and tend to pollute one area and that area stays polluted,鈥 he says.
鈥淗owever, PFAS are very mobile in the environment. So, we end up having contaminated drinking water suppliers in locations where PFAS may not have contaminated the groundwater initially but just where it鈥檚 ended up because they don鈥檛 break down.鈥
To help regulate this, government bodies such as Food Standard Australia and New Zealand and National Health and Medical Research Council have set health-based guidance values (HBGVs) indicating the amount of a chemical聽a person can consume on a regular basis over a lifetime without any significant risk to their health.
In Australia, the , a regulated chemical within the PFAS classification, is set at 560 nanograms per litre. In comparison, just last week the announced the proposed National Primary Drinking Water Regulation 鈥 putting forward a new of four nanograms per litre of PFOA in聽drinking water.
While the proposal is still subject to public consultation, if successful it would聽mark聽the first time in 26 years that the EPA聽set legal limits for a contaminant in drinking water. It would聽also be a significant reduction from the聽previous limit of 70 nanograms per litre.聽聽
Prof. Khan says these values are a moving target as Australia tries to keep up with the United States EPA and similar agencies across Europe.
鈥淚t鈥檚 hard for Australia to keep up with these values as they seem to get lower and lower every year,鈥 he says.
鈥淏ut there is a rigorous process to keep monitoring these values and we take on a balance-of-evidence approach. If there was really compelling evidence that we need to update the guidelines, then we will do it.鈥
Globally, there is a movement to limit and phase out the use of some forms of PFAS. However, that doesn鈥檛 address the issue of the large amounts still found in our environment today.
Some studies have reported that even in one of the world鈥檚 most remote locations such as Antarctica, concentrations of PFAS have exceeded some of the most stringent health-based values, says Prof. Khan.
He says while it鈥檚 not impossible to clean up the substances, it鈥檒l be a question of whether governments would want to invest the聽amount of energy, carbon footprint and money to do so.
鈥淐urrent water remediation processes might not be sufficient as there is still the problem of what to do with the PFAS once it鈥檚 been extracted,鈥 he says.
鈥淚f you consider our water treatment processes for a contaminated groundwater site, we can use membranes or ion exchange resins to separate PFAS from the water 鈥 leaving you with clean water.
鈥淏ut you end up with PFAS as a waste stream which is still a massive problem.
鈥淵ou could bury it in the ground, but it鈥檒l still end up in your groundwater supply which is where the problem started in the first place.鈥
While there are incineration processes to destroy PFAS, it would require a massive investment of energy and money 鈥 and come at the cost of producing more greenhouse gas emissions.
鈥淚t鈥檚 very difficult to develop a treatment process that actually destroys the PFAS because most likely you鈥檙e producing smaller fluorinated compounds that will end up in the atmosphere anyway,鈥 says Prof. Khan.
鈥淧lus, we would need to factor in how much extra carbon footprint we鈥檒l be contributing if we were serious about going down this path.鈥
Prof. O鈥機arroll says just because we can use PFAS, doesn鈥檛 mean we should.
鈥淲e probably don鈥檛 need to use all these anthropogenic chemicals as much as we do,鈥 he says.
鈥淎s modern consumers, if we really want to limit our use of PFAS, we need to do our research and look into what products are made from because there is PFAS in a lot of things that you wouldn鈥檛 even consider.鈥
There鈥檚 also still the question of finding a safe yet effective substitute for PFAS.
Prof. Khan says there is rapid development of alternative chemicals which are still in the per-fluorinated group 鈥 they鈥檙e just a different kind to the ones presently regulated in the market.
鈥淲e鈥檙e seeing the emergence of the 鈥榥ext generation of chemicals鈥 which are moving away from acid-based and sulphate-based chemicals,鈥 he says.
鈥淗owever, the caveat is that we don鈥檛 know what the long-term impact of these newer chemicals is going to be 10 years down the track. It may end up causing just as many problems as the ones we鈥檙e dealing with now.鈥