They can be found on raincoats, non-stick pans and plastic packaging. In the last 50 years, PFAS – short for per- and polyfluoroalkyl substances – have made their way into many of our everyday objects. Dubbed "forever chemicals", they're extremely persistent and can stay in the air, water and soil for decades, harming the environment and ultimately our health. Is PFAS pollution irreversible? And what can we do to protect ourselves? We take a closer look in the edition of Down to Earth.
Belgium’s worst environmental scandal
Thomas Goorden, an activist and environmental researcher, helped uncover what has arguably become one of Belgium’s worst environmental scandals in recent memory. For nearly half a century, chemicals company 3M produced PFAS out of its factory in Zwijndrecht, in the outskirts of Antwerp. Now it's become a hotspot for PFAS contamination.
The problem came to light when the government decided to dig a tunnel connecting the two sides of the city. Extremely high levels of PFAS were detected in the soil, triggering a public outcry that has since turned into a criminal investigation.
Goorden describes it as an oil spill, "but spread out over 50 years".
"In the last decades, 3M has been polluting this entire area," he explains. "Emitting PFAS into the air and that all ended up depositing in the neighbourhood."
He takes us to meet Eduard D'Hollander, who lives less than a kilometre away from the 3M factory. D’Hollander, his wife and daughter are among several local residents who have had their blood levels checked for PFAS exposure.
"PFAS levels should not exceed 6,8 micrograms, he says. "I had 750 and my wife 1,200. We don't know what the consequences will be."
The extent of contamination in Europe
PFAS are a group of at least 10,000 man-made chemicals, according to the European Chemicals Agency. What makes them so unique is that they're made of carbon and fluorine atoms, one of the strongest bonds out there, making them almost indestructible. They can resist intense heat, repel water and stains, making them the ideal chemical component for the manufacturing of many of our everyday objects, such as raincoats, food packaging or non-stick pans.
Those same properties are what makes PFAS so dangerous. Once they get released into the environment from factories, they're so persistent that they won't naturally break down, building up in the soil and water. It's the perfect recipe for an environmental and public health disaster. According to recent estimates, some 4.4 million tonnes of PFAS could end up in the environment over the next 30 years unless action is taken.
But how many factories, rivers and plots of land have already been contaminated? That's exactly what a group of investigative journalists from 13 countries wanted to find out. As part of the Forever Pollution Project, they created a map of all confirmed and presumed cases of contamination across Europe. It’s the first time someone has ever tried to map and assess the extent of PFAS pollution on the continent.
"The result is quite spectacular, in the sense that there are very few places that have been spared by this pollution,” says Stéphane Horel, an investigative journalist at French daily Le Monde and a member of the Forever Pollution Project.
The figures speak for themselves: a total of 17,000 contaminated sites and 21,000 others presumably contaminated. There's a category for so-called hotspots, above 100 nanograms per litre or per kilo of PFAS, which includes places like the 3M factory in Antwerp.
"These are places where authorities should intervene immediately," she warns.
PFAS considered endocrine disruptors
So what does it mean for our health? Francesca Mancini, an epidemiologist at the French National Institute of Health & Medical Research (INSERM), has been studying the effects of PFAS exposure, particularly on women's health.
A group of 100,000 women between the ages of 40 and 65 were recruited for the study in 1990 and have been continuously monitored ever since. Scientists believe that approximately 80 to 90 percent of our exposure to PFAS happens through food and water.
"PFAS are endocrine disruptors, which means that they disrupt the body's hormonal functions," says Mancini.
"The strongest evidence gathered so far relates to the link between PFAS exposure and our immune system, especially children’s immune response to vaccines," she adds. In other words, children who are more exposed to PFAS are less protected by vaccines.
Other studies show a potential link between PFAS exposure and breast cancer in women.
The health risks posed by PFAS are far from new. And thanks to the work of scientists, certain subgroups of the toxic chemicals, such as PFOS or PFOA, were eventually banned.
"The ultimate goal of our research is to generate scientific evidence, evidence strong enough to convince decision makers to act. And eventually extend the ban to several molecules that are part of the same family," she concludes.
Decontamination efforts in Antwerp
All around Antwerp, nearly every construction site has become an environmental hazard and is now required to clean up the groundwater below.
Colas Environment is one of the construction companies having to deal with the aftermath of PFAS pollution. As part of ongoing roadworks, they need to pump groundwater out. Normally, it would then be released back into the water system. Except this water is now heavily polluted and must be cleaned.
Water is sent directly into large tanks equipped with carbon filters that will capture pollutants, including PFAS. Once the filters are saturated with PFAS, the remaining carbon must be incinerated.
It's hard to see how this could become a solution in the long term. The carbon filters will just absorb the pollutants, but won't destroy them, explains Arnault Perrault, Managing Director at Colas Environnement.
Water that will continue to seep back into the aquifer will become contaminated once again by the soil.
"If we wanted to turn this into a decontamination site, we would have to be able to tackle the pollution at the source, underground."
Making irreversible pollution reversible
In a bid to find a long-term solution, Colas Environnement has partnered with researchers from the French national geological survey BRGM. We met Julie Lions, who showed us their experimental research platform, known as Prime. It's a large container filled with soil where scientists have purposefully injected PFAS found in firefighting foams.
Through various experiments, the team will try to remove the toxic chemicals using a gel-like substance, before applying a second treatment capable of destroying any remaining pollutants in the soil.
"With this gel, we are able to remove 95 percent of the PFAS present in the soil," says Lions. Other methods include heating up to soil at more than 1,000°C, she adds.
The price of decontamination remains a major stumbling block.
"Towards the end of the investigation, I said to myself that I should try to put a price tag on the levels of contamination found in Europe," recalls Stéphane Horel from French daily Le Monde.
"I stopped doing the math when I'd reached several hundred billion euros. That's when I realised it was just so much money that nobody can actually tell how much it will cost to rid the environment of these chemicals."
