Australians may not realise it but they are sharing their food, homes and even their bodies with potentially harmful substances dubbed forever chemicals.
Technically they're not forever but are long-lived and don't easy break down in the environment.
The chemicals are contained in countless everyday products and known as per- and poly-fluoroalkyl substances, or PFAS for short.
Experts say their use in everything from food packaging and non-stick cookware to cosmetics and carpet, mean they're now part of us - literally.
"We all have some PFAS in us," Jen Martin, who's involved in researching exposure in livestock, told a recent conference in Sydney.
"They are ubiquitous in the environment, and in humans. Many of these can bioaccumulate (become concentrated inside the bodies of living things), are persistent and can have toxic properties."
The Newcastle Herald has extensively reported on the health issues of residents living around the Williamtown RAAF Base where PFAS chemicals were used for fire fighting training for many years.
During the federal election campaign, Labor committed to an independent review into land use options around the defence bases with a view to assisting those affected by PFAS contamination.
Authorities can't agree on how many PFAS there are with estimates ranging from 4000 to 8000.
What's certain is they are now present in rainwater and snow in even the world's most remote locations, where there are no obvious sources of contamination, a Stockholm University study recently found.
Worse, they've been found at levels that exceed US drinking water guidelines and scientists say there's an urgent need to rapidly restrict their use.
The jury is still out on human health effects but many nations now warn of increased cancer risks and advocate limiting exposure to chemicals in use since the 1940s.
The EU's environment agency says PFAS can lead to health problems such as liver damage, thyroid disease, obesity, fertility issues and cancer.
Of the relatively few well-studied PFAS most are considered moderately to highly toxic.
The US Environmental Protection Agency says certain PFAS are known to cause human health risks.
The group points to studies showing certain exposure levels may heighten cancer dangers, hurt fertility and birth weights and accelerate puberty.
Australia - which is about to get a new draft of its national management plan - appears to be more cautious.
The federal government's expert health panel points to "fairly consistent reports of an association with several health effects" while noting they are "generally small and within normal ranges for the whole population".
"There is also limited to no evidence of human disease or other clinically significant harm resulting from PFAS exposure at this time," the panel found.
It's also concluded there's no evidence suggesting an increase in "overall cancer risk". Regardless, there's a vast amount of work being done to assess Australia's PFAS problem, what levels are already locked in, and what should happen to stop an "emerging" contaminant becoming more entrenched.
One critical concern is how to limit further exposure given Australians already have at least three types of PFAS in their bodies.
Experts hope the latest draft of the PFAS plan, due for release this month, will contain improved risk management systems.
One of the many things it's expected to address in greater detail is the issue of PFAS in biosolids, a by-product of the wastewater treatment industry that's routinely repurposed as fertiliser for Australian farms.
Biosolids are essentially treated and dried sewage sludge - a mud-like residue the reflects everything Australian families put down the drain or sewer, including poo and dirty water used to wash dishes, clothes and bodies.
It can also include the leftovers from water-borne trade waste.
Once the sludge is treated and dried it's spread over the nation's farmlands to improve soil condition. Last year, more than 70 per cent of the 349,000 tonnes of dried solids was disposed of in this way.
Water companies say reusing the waste has many benefits, including reducing reliance on man-made fertilisers, but they also know it's distributing low levels of PFAS.
They say the process is carefully managed to guard against risky levels of contamination.
But experts say the existing system of state-based guidelines is not good enough and must be consistent nationally.
"We don't have consistent guidelines in Australia for biosolids quality and risk management," University of NSW professor Stuart Khan says.
"They are sort of all over the place.
"In NSW our guidelines date back to the 1990s and haven't really been updated since.
"There are big gaps.
"If we don't sort out our risk management, and make sure we practise safe handling of biosolids particularly where it's being reused to grow food crops, we might run into difficulties in the future."
At a biosolids symposium in Sydney last week, PFAS researcher and University of Newcastle Professor Ravi Naidu explained how typically low and safe levels of PFAS found in Australian bodies could rise over time.
"The question is really the exposure pathways. The utensils, the food you eat, the water you drink. If all of these introduce PFAS into your system, you'd become an outlier," he told delegates.
"Exposure pathways, and duration of exposure, they all play a significant role in risk."
Prof Naidu was to present a new study on PFAS levels in vegetables sold at Sydney markets at a conference in Adelaide this week.
Last year's Australian Total Diet Study, conducted by Food Standards Australia New Zealand, tested for 30 different types PFAS in 112 common foods sourced from all over Australia.
It found consumers' exposure to PFAS through food and beverages is very low and poses no food safety concerns.
World needs UN body for chemical pandemic
THE human race is in the grip of a "chemical pandemic" on par with the existential threat of climate change, an international conference on contamination has been told.
More than 500 scientists from 28 countries have gathered in Adelaide to hear shocking statistics about the scale of chemical use worldwide and how it's affecting human and environmental health.
Delegates heard 350,000 chemicals are currently used worldwide with 2000 new ones added each year. They have polluted every ecosystem on the planet, and are routinely found in the bodies of humans and animals.
"These enter our bodies with every breath we draw, each meal and drink, the clothes we wear, the products we adorn ourselves with, our homes, our workplaces ...," said veteran science writer Julian Cribb, who's long documented the chemical "tsunami".
"The UN Environment Programme cautions few of these chemicals have ever been properly tested for health and environmental safety."
He said the output of industrial chemicals had doubled since 2000, to around 2.5 billion tonnes a year, and is forecast to triple by 2050.
"It is five times the scale of our climate emissions. For it's sheer size and global ramifications, it is the most under-rated, under investigated, and poorly understood of the 10 catastrophic threats that now face humanity."
Mr Cribb says the human race needs the chemical equivalent of the UN's Intergovernmental Panel on Climate Change if it is to stand a fighting chance.
"It is clear that governments do not have the capacity or the will to regulate a global toxic flood.
"The only people who can discipline them (chemical polluters) are the consumers by refusing to buy their products."
He said surveys by the US Centres for Disease Control had found flame retardants, BPA from plastic bottles and traces of non-stick cookware coatings in Americans of all ages, including newborns.
Earlier, delegates heard the world has an estimated 10 million contaminated sites, including 200,000 in Australia. That's before the world has fully come to terms with PFAS - a family of thousands of chemicals that don't readily break down.
"We really don't know the impacts of these chemicals individually, let alone when they combine with each other," said Tony Circelli, chief executive of South Australia's Environment Protection Authority.
"We've got nanoparticles, we've got microplastics - our food chains are getting overwhelmed by all this."
PFAS is shorthand for per- and poly-fluoroalkyl substances. They've been detected in air, water, food and animals, including in Australia after decades of use in everyday items from food packaging to cosmetics and carpet.
They have been associated with serious human health risks including some types of cancer, liver and thyroid issues, fertility problems, early onset puberty and low birth weights, among other things.
The Australian government is about to release the third draft of its national plan to manage PFAS.
WHAT ARE PFAS CHEMICALS?
* PFAS is the short-hand name for a family of manufactured chemicals used in industry and consumer products since the 1940s
* There are thousands of types of per- and poly-fluoroalkyl substances (PFAS) and they are valued for their heat, water and stain repelling properties
* They're present in a vast range of industrial and consumer products including food packaging and non-stick cookware to make-up, shampoo, paints, sealers and stain-resistant carpets and fabrics
WHY ARE REGULATORS CONCERNED?
* PFAS are sometimes referred to as forever chemicals because they are long-lived, and don't easily break down in the environment
* They are often toxic and can accumulate in plants, including agricultural crops, and in the bodies of animals including humans
* Experts say they are now ubiquitous, meaning they are found everywhere on earth
* PFAS have been found in Antarctica and in Arctic Sea ice, where there is no obvious source of contamination
HOW DOES IT AFFECT HUMANS?
* Scientists suspect PFAS may pose broad health risks including cancer but research is inconclusive so far
* The US Environmental Protection Agency cites peer-reviewed scientific studies that have shown exposure to certain levels of PFAS may lead to increased risk of some cancers, including prostate, kidney, and testicular cancers
* It points to other studies showing there may be increased risk of fertility issues, developmental effects in children, immune system impacts, hormonal interference and increased cholesterol levels and/or obesity risks
* The EU's responsible agency says PFAS can lead to problems such as liver damage, thyroid disease, obesity, fertility issues and cancer
* It says of the relatively few well-studied PFAS most are considered moderately to highly toxic
* Australia's health panel for PFAS says there are fairly consistent reports of an association with several health effects while noting they are generally within normal ranges for the whole population.
* It says there's no existing evidence suggesting an increase in overall cancer risk
* Australians generally have at least three types of PFAS in their bodies
* PFOS, PFOA and PFHxS are readily absorbed through the gut, and once present in a person's body it takes two to nine years, depending on the study, before levels go down by half, even if no more is taken in
* Australia decided about 14 years ago to phase out the most concerning PFAS and recommends ongoing exposure should be minimised
WHAT ARE THE ENVIRONMENTAL CONCERNS?
* PFAS have been shown to be toxic to some animals and can bioaccumulate and biomagnify in some wildlife, meaning animals higher up the food chain may accumulate high concentrations in their bodies
* The toxicity, mobility, persistence and bioaccumulation potential of PFAS means they have the potential to cause serious environmental and human harms depending on exposure levels
* PFOS and PFOA are highly persistent and can travel long distances in water and in the air
Floodwater plays role in toxic spread
Climate change is aiding the spread of chemical contaminants by fuelling floods and other severe weather events, an international conference will hear.
More than 500 experts from 28 countries are meeting in Adelaide to discuss the decline of human and environmental health due to the colossal use of man-made chemicals worldwide.
On Monday, delegates heard 350,000 chemicals are currently used worldwide with 2000 new ones added each year and they are now routinely found inside the bodies of humans and animals, and in all ecosystems including the human food chain.
The output of industrial chemicals had doubled since 2000, to around 2.5 billion tonnes a year, and is forecast to triple by 2050.
Yesterday's program concentrated on how climate change is exacerbating the already alarming spread of contaminants.
Hydrogeologist Scott Warner is a researcher with the Global Centre for Environmental Remediation at the University of Newcastle and has long studied groundwater contamination.
Extreme weather events, such as flooding, drought and even bushfires, can have serious effects on groundwater quality.
"Floods can cause a rise in the water table that allows contaminated groundwater to emerge or flow to areas not yet affected by the contamination," Mr Warner said.
"Floods can also cause overflow from sewers and other potentially contaminated areas."
Droughts, which are expected to become longer and more severe under climate change, can also fuel the contamination problem by lowering the water table and concentrating the contaminants in smaller volumes of groundwater.
That can create "smear zones" of contaminants within aquifers.
"These zones can affect groundwater later when more water enters after rain and snowmelt," Mr Warner said.
"Some ecological species can tolerate diluted levels of contaminants, but when the contaminants become concentrated, plants and animals may be at greater risk."
Sea level rises, which are already being recorded globally as the planet warms, can also cause seawater to intrude into freshwater systems that are linked to groundwater, potentially affecting reserves further inland.
In order to avoid immediate and long-term damage to people and the environment, scientists must conduct more regular monitoring of groundwater and use more sustainable and durable monitoring systems, Mr Warner said.
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