How scientists in Flanders are unraveling the journey of persistent pollutants with innovative tools

Per- and polyfluoroalkyl substances (PFAS) – sometimes called “forever chemicals” – have made headlines for their stubborn presence and harmful effects on both nature and people. This PFAS family has many members (over 10.000), and each member behaves in its own way, making this a particularly challenging set of chemical molecules to deal with. In Flanders, a region with a history of active industry, PFAS emissions have seeped into the environment, traveling from factory stacks into the air and eventually settling into our soils and water. But exactly how PFAS move through the environment – from air, to earth, to plants, and even down to groundwater – has long been a puzzle that scientists are eager to solve.

A collaborative solution: the Flemish use-sase

Enter the PFAS use-case in SOILPROM, a pioneering setting where experts from VITO and Wageningen Research (WR) have teamed up to create an integrated modeling framework. Their mission: to follow PFAS across every stage of its environmental journey and offer a clearer, more complete picture of how these pollutants behave in the real world.

What’s special about their approach? Instead of looking at just one piece of the PFAS puzzle, the team connects emission and deposition models with simulations of soil leaching and plant uptake, all while factoring in each compound’s unique chemical traits and local environmental conditions. This means more reliable predictions and a deeper understanding of PFAS contamination across the entire atmosphere–soil–plant–groundwater spectrum.

Innovative advances: getting deposition right

One big step forward is how the project tackles PFAS atmospheric deposition. To better estimate how much PFAS settles onto the soil, scientists re-worked both dry and wet deposition processes using the latest research and newly gathered data from Flanders. At advanced monitoring sites near Antwerp, they measured PFAS in the air and the amount that lands on the ground at the same time, allowing them to calculate realistic deposition speeds for different PFAS compounds.

This hands-on data reduces uncertainty and ensures that soil contamination models start with realistic “upper boundary” conditions. Ultimately, these improvements mean scientists can better predict how PFAS move from the air into the soil below.

Figure 1: The region of interest for the use-case will be an industrial site in Flanders (Picture by Thierry Monasse/Getty Images)

Modeling the journey: from sky to soil to water

Using these improved deposition values, the team then used an atmospheric dispersion model (IFDM) to predict exactly where different PFAS would land around sources like factories.

The next step: linking IFDM’s results with the GeoPEARL soil leaching model. By creating a two-dimensional simulation grid over our study-site scientists can track PFAS migration from the surface down through the soil, and eventually toward groundwater. These detailed, location-specific simulations are a far cry from older methods that assumed uniform deposition everywhere. Meanwhile, WR has been busy refining how the models represent the various members of the PFAS family getting absorbed by soils and taken up by plants, making the overall system even stronger.

Impactful insights for policy and the environment

This combined modeling does not just trace PFAS movement, it also lets policymakers test intervention and clean-up strategies and see how they affect ecosystem services. By connecting contamination trends to the benefits provided by healthy ecosystems, the Flemish use-case arms decision-makers with science-based guidance to prioritise effective mitigation and remediation in regions affected by PFAS.

In summary, the work in Flanders sets a new standard for understanding and managing the complex issue which is PFAS pollution. It’s a hopeful step towards cleaner environments and smarter policies, showing how collaborative science can make a real-world difference

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