ARCHE Consulting’s Marnix Vangheluwe, Nathalie Briels and Hadewych Vanhooren discuss the origins and spread of the PFAS crisis in Flanders, Belgium.
Over the years, a trend of decreasing Tolerable Weekly Intake (TWI) values for PFOA (perfluorooctanoic acid) and PFOS (perfluorooctane sulfonate), persistent chemicals within the PFAS group, has been observed (Figure 1) (Brunn et al, 2023)¹. This is mainly due to new discoveries regarding the substances being evaluated.
The origins of the PFAS crisis in Flanders
The significant shift towards lower TWI values for PFAS has led to the development of lower safety thresholds. It was therefore not surprising that this race to the bottom triggered a PFAS crisis in Flanders (Belgium), in the context of PFAS measurements carried out on soil parcels of large-scale infrastructure works underway around Antwerp (Oosterwheel project). The Oosterweelverbinding project is a large-scale infrastructure project in Antwerp, Belgium, designed to complete the Antwerp Ring Road (R1) and improve traffic flow in the region (Figure 2).
The scale of the PFAS contamination was officially revealed during excavations between 2018 and 2021, and the origins of the widespread PFAS contamination could be traced back to 3M’s 3M production site in Zwindrecht. From the early 1970s until 2002, PFOS-containing products were primarily produced at Zwindrecht 3M. After 2002, production of PFOS was stopped, but many more mobile short-chain PFAS compounds were produced until 2024 when a decision was made to stop all PFAS production at the 3M Zwindrecht plant.
Introduction to safety measures
In response to the PFAS crisis, the Flemish government has appointed a PFAS Commissioner from June 2021 to December 2022. The Commissioner was tasked with coordinating a structured approach with partners within the Flemish Government, authorities, government organizations and other stakeholders. The Secretary developed a temporary policy framework to address PFAS contamination in various environmental zones and established a series of “no-regret measures” around 1.5 to 5 kilometers around the site.
These “no-regret steps” involve:
food
Do not eat eggs from your own chickens or eat small homegrown livestock. Do not use compost made from material from your own garden (less than 1.5 km).
groundwater
Do not use well water for drinking, making tea, coffee, ice, or cooking.
soil and green waste
Avoid resuspending the soil. For example, make sure the soil is planted or covered with bark. Children should not play on uncovered soil.
health
Maintain good hygiene: Wash your hands regularly and thoroughly, especially before eating, after playing outside, and after working in the garden. Clean the indoor environment regularly with a damp cloth.
blood monitoring campaign
As part of the health assessment, a major blood collection campaign is being set up. The first survey of 796 adults (adults only) living within 3 km of a 3M site was conducted in 2021. A larger sampling campaign was carried out with 8,568 people in the period 2023-2025 (Eurofins, 2025). The results showed a clear increase in PFOS blood concentration the closer to the site (Figure 3).
For the assessment of internal exposure to PFAS substances, the Human Biomonitoring Committee of the German Environment Agency (HBM Committee, 2020)⁴ has developed toxicologically valid assessment values (HBM-I and HBM-II values). The HBM-I value corresponds to the concentration of a substance in human biological material below which, according to the current evaluation status, no adverse health effects are expected (i.e., PFOS 5 ng/mL and PFOA 2 ng/mL). ⁵ In contrast to HBM-I values, HBM-II values (i.e., PFOS 20 ng/mL and PFOA 10 ng/mL) and women of childbearing age: PFOS 10 ng/mL and PFOA 5 ng/mL correspond to concentrations of the substances in human biological matter, above which they may cause health problems that are considered relevant to the affected individuals. Blood test results showed that 70% of adults and 80% of children had PFOS/PFOA levels below HBM-I. Approximately 30% of adults and 20% of children have PFOS/PFOA levels, and negative long-term health effects cannot be ruled out.
Risk assessment and remediation
On October 29, 2021, 3M was placed on safety measures to suspend all processes that emit PFAS unless it can be proven that the processes can be restarted without adversely impacting human health or the environment. In this regard, ARCHE Consulting was appointed as an independent PFAS expert with the approval of the Long-term Care Agency to assess all 3M’s PFAS-related data regarding emissions to air, water and soil and estimate the potential impact on the population near the 3M site.
With the help of the IMPACT model, potential atmospheric concentrations and PFAS deposition fluxes were calculated by a simple Gaussian plume model used in Flanders (Belgium) ARCHE. The latter were then converted to soil and groundwater concentrations by ARCHE. At the time of the evaluation, there were no appropriate inhalation and deposition thresholds available for all PFAS compounds of interest. ARCHE Consulting, in collaboration with VITO, carried out a study to derive values for the maximum permissible concentrations of PFAS in air for the Flemish Environment Agency (Vanhooren et al, 2024).
In addition to these air quality criteria, sedimentation assessment values were also derived for the first time (Van Holderbeke et al, 2024). ⁷ These values represent the maximum amount of PFAS that can be deposited on the ground per square meter per day (Table 1).
In 2024, 3M Zwindrecht decided to stop all processes emitting PFAS at its sites. A remediation agreement and remediation code with 3M and other local stakeholders has been established for a total of €571 million, which includes soil excavation to a depth of 70 cm in the residential garden, the use of non-invasive remediation techniques and long-term monitoring in adjacent natural areas.
But Flanders’ PFAS crisis did not stop there. As a result, a PFAS action plan was developed for the entire Flemish region. This strategic plan, which includes 50 actions from 2022 to 2024, brings together various government partners to turn PFAS policy into concrete outcomes. For example, the Substances of Very High Concern Hub was created. This is a function-based governance approach for the PFAS mission, represents a new structured approach to policy on substances of very high concern, and builds on the working methods introduced by the Secretary in recent months.
In addition, programs are being built to monitor the health of local populations over time. PFAS data is now available through the PFAS Explorer. This is an open data environment of the Flemish Subsurface Database, built as a central system where measurement data of PFAS in all different environmental compartments are compiled and visualized. Additionally, a dedicated PFAS website has been established to ensure that all information regarding PFAS issues is available and continuously updated. All information and insights will be shared with the public through the website.
Finally, the Knowledge Center (KIS) for innovative PFAS remediation technology was established to further build on the extensive know-how that Flanders has developed over the years. This highlights a distinct butterfly effect.
References
Brunn H, Arnold G, Körner W, Rippen G, Steinäuser KG, Valentin I, 2023. PFAS: Persistent, bioaccumulative, and mobile. Review the status and need for phase-out and remediation of contaminated sites. European Environmental Science, 35 (1)20. Eurofins, 2025a. Consortium Eurofins, Eurofins Belgium, Eurofins Forensics, Dr. Bernard Dirk, L-BioStat, Dr. Kate Hoffman, Dr. Veronica Vieira, Dr. Scott Bartell (2025), Large-scale PFAS blood testing near the 3M factory in Zwindrecht – Results report commissioned by the Ministry of Health, 210p. Eurofins, 2025b. Photo taken from the webinar EUROFINS:
https://www.youtube.com/watch?v=tHuNnJFluY8 HBM, 2020. HBM-II values of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) in plasma. Statement by the Human Biomonitoring Committee of the German Environment Agency HBM, 2016. HBM I values of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) in plasma. Bundesgesundheitsbl 59, 1364 (2016). https://doi.org/10.1007/s00103-016-2437-1 Hadewych Vanhooren, Marnix Vangheluwe, Mirja Van Holderbeke, Arno Vanderbeke, Anthony Purece, Lieve Geerts, Ingeborg Joris, Michiel Maertens, Katleen De Brouwere, Kaat Touchant, Jan Peters, Patrick Berghmans, 2024. Confirming PFAS with Trustee OMGEVINGSLUCHT – OMGEVINGSLUCHT Mirja Van Holderbeke, Arno Vanderbeke, Anthony Purece, Lieve Geerts, Ingeborg Joris, Michiel Maertens, Katleen De Brouwere, Kaat Touchant, Jan Peters, Patrick Berghmans, Hadewych Vanhooren, Marnix Vangheluwe, 2024 year. Preparation for checking PFAS at depository – Depository
author
Marnix van Helwe
Natalie Briels
Hadewicz Vanheuren
Please note: This is a commercial profile
This article will be published in an upcoming PFAS Special Focus Publication in April.
Source link
