PFAS contamination in agricultural soils

Just over two decades ago, using sewage sludge in agriculture in Switzerland was considered an effective way of returning nutrients to the cycle while utilising residues from wastewater treatment. At the time, it was not realised that this could result in the distribution of persistent pollutants such as PFAS over large areas of agricultural land.

Contamination of fertile agricultural land, sometimes over large areas, renders traditional remediation methods such as soil replacement or soil washing impractical for technical, environmental and economic reasons. Simply waiting is not a satisfactory solution either: PFAS do not degrade, meaning that affected farms may no longer be able to market their produce, or only to a limited extent, which would have immediate consequences for their economic survival.

Reducing transfer into livestock and food

UMTEC is therefore seeking potential solutions in laboratories, indoor cultures and field trials, while maintaining close contact with leading research groups abroad. However, solutions cannot simply be transferred; what is technically feasible and permitted elsewhere may not comply with Swiss and local legal, agricultural and environmental frameworks. The challenge is consequently interdisciplinary, encompassing chemical, biological, agricultural, veterinary, human toxicological, economic and political issues.

The first step is to research how PFAS uptake from soil into fodder and crops, and subsequent transfer into livestock and food, can be reduced. Although the contaminants initially remain in the soil, their bioavailability and entry into the food chain will be reduced to such an extent that the food produced will once again comply with applicable limit values. While this does not solve the PFAS problem in soil, it could provide affected farms with much-needed prospects in the short to medium term while buying time for long-term remediation solutions to be developed.