Across Europe, scientists and citizens are uncovering a hidden legacy of contamination beneath their feet. From Denmark’s first PFAS crisis to a new generation of soil-mapping initiatives, a continent is learning to see — and stop — the pollution it once ignored

The ground beneath our feet can hide pollution. How can we map and prevent contamination?

Before 2021, Korsør was known mostly as a quiet, picturesque town on Denmark’s western coast — a place of grazing cows and calm waters. Few imagined it would become the epicentre of the country’s first PFAS contamination. At the time, almost no one in Denmark had even heard of PFAS, the so-called “forever chemicals”. If you Googled it, you got five hits. “Before our contamination, PFAS didn’t exist as a subject in Denmark,” recalls Kenneth Nielsen, a local biology teacher and former chairman of Korsør Cow Grass Association.

The discovery was made almost by coincidence. “A journalist called me asking if I had heard something about contamination of the ground where our cows were out in the summer,” Nielsen says. “I said, I have no idea what you’re talking about.” The cows grazed on land near a firefighting training site. It was later found to be heavily polluted with PFAS foam residues that had seeped into the soil and water for decades. Nielsen offered to have his meat tested. A week later came the call that turned their lives upside down and changed the way Denmark is treating forever chemicals.

They told him the test results of the meat: “It’s bad. It’s really, really bad. You can’t eat that meat. It’s not suitable for human beings, not even animals.” The city authorities quickly confirmed the results and issued warnings, but no one could explain what PFAS really was, or what risk it meant for those who had eaten the meat. “It was the most terrifying weekend I’ve ever had,” recalls Nielsen. “You just sit there thinking, what have we done to our families?”

He called his doctor on Monday, only to get a surprising answer. “I said, I have PFAS in my body — what should I do? And she said, ‘I can’t help you.’ Nobody knew what PFAS was or how to treat it. We were left alone.”

Nielsen did not give up; his persistent search for answers from the authorities and doctors is part of the reason why we know more about PFAs today.

From local tragedy to European

What started with a single steak from a family freezer soon became a national, then continent-wide wake-up call. “PFAS are mobile, persistent and toxic substances,” explains Hans Peter Arp, an environmental chemist at the Norwegian Geotechnical Institute and the Norwegian University of Science and Technology. “They are often called forever chemicals because they don’t break down naturally and can accumulate in animals, plants and humans over time, spreading silently through soil and water.” “In soil, they don’t degrade,” adds Arp. “If no action is done, they’ll be there beyond our lifespans — and our children’s. Unlike oil spills or metal pollution, PFAS contamination is invisible. “It’s not like an apocalyptic landscape,” Arp adds. “PFAS goes into the plants, but it doesn’t kill them. You can’t see it, but the animals — and the people — are contaminated.”

Searching for solutions

The Korsør crisis compelled Denmark to act — and drew European scientific attention. Across Europe, estimates suggest 60 percent of soils are unhealthy, making such efforts vital. Within ARAGORN, an EU project addressing soil contamination and remediation, Korsør is considered a “zero site” — a starting point for learning how to clean up and prevent similar contamination elsewhere.

“Our approach is co-creation,” says Arp. “We work with local experts, community members, and site owners to identify their concerns and goals. Then we combine that with our technical expertise to find a pathway forward.” Xenia Trier, ARAGORN’s coordinator, says the project is part of a broader European soil mission aimed at achieving healthy soils by 2050.

“Soil sits at the interface between where we live and have our activities, it supports our food production, it’s above water,” she explains. “If we want to combat contamination, we must first avoid adding new pollution — but also deal with what’s already there. Prevention is key, but so is reducing risk for people and ecosystems.”

That means mapping hotspots, prioritising urgent areas for remediation, and testing different methods before any large-scale work begins. “There’s no one-size-fits-all solution,” Trier says. “Decisions must include the people who actually live on the land. Co-creation ensures solutions are realistic, effective, and fit for purpose.”

“Without community involvement, it might not be a success,” Arp who also works within the ARAGORN project stresses. “You can’t just come in and fix it — you have to work with the people who live with it.”

A European effort

The lessons from Korsør are now shaping European policy. The European Union aims to phase out PFAS from firefighting foams, textiles, packaging, and even some industrial systems.

In October 2025, the EU adopted its first Soil Monitoring and Resilience Directive — a law requiring Member States to track soil health and map contaminated sites. ARAGORN supported it in various ways, for example, they helped with proposals on which chemicals should be regulated and what should be the principles behind it.

“We’re still at the beginning” says Trier. “We need a harmonised framework so that countries act consistently — not just where contamination has already been found, but to prevent new cases. If one law says one thing and another says the opposite, it frustrates land managers and slows down action. Harmonised, realistic regulation is crucial if we want to make progress.”

Prevention is the central playfield

“Factories that make PFAS need to reduce their emissions, or, ideally, stop making PFAS, make something else,” Arp says. “Some industries say they can’t replace PFAS in certain uses. But others can be restricted as soon as possible — like fluorinated gases or textiles in clothing. These are the things that we have to reduce right away.” Meanwhile, scientists are mapping dozens of sites across Europe that may already host PFAS pollution — a process inspired by The Forever Pollution Project’s cross-border investigation. “Mapping is essential if we want to act efficiently,” says Trier. “It helps us see where the problems are, and where intervention matters most.”

A high price for awareness

Four years on, Korsør remains a warning and a lesson. The land is monitored, and some remediation trials have begun, but for residents like Kenneth Nielsen, the emotional and physical impact endures. “I’ve eaten this meat for 17 years,” he says. “You can’t see PFAS, you can’t smell it — but it’s in us. It changes how you look at your home, your food, even your country.” He keeps speaking out, hoping it helps others avoid the same fate. “If our story means no one else has to go through this,” Nielsen adds, “then at least something good came out of it.” Stories like Nielsen’s and his community are a reminder of what is at stake. “Science and regulation can feel abstract, it may just be like numbers” Trier says. “But when you listen to people in places like Korsør, you see the human impact”.

By Katalin Tornai