Due to their persistence, widespread use, and toxicity per- and polyfluoroalkyl substances (PFASs) are a reason of concern for the environment and human health. They are a major challenge for chemical soil protection. To set soil threshold values and prioritize measures, knowledge on PFAS concentrations in soil is crucial.

For Switzerland, only information on background concentrations of PFASs in soil has been available so far^[1]. To have a better understanding of the PFAS distribution in Swiss soils, a data collection of measurements of PFASs in Swiss soils has been initiated.

Measurement results of over 1000 samples were gathered with most of the data originating from cantonal measurement campaigns. The objectives of the campaigns were varied, some assessing PFAS background concentrations in soil, while others screened for potentially contaminated sites or further assessed known contaminated sites.

This study summarizes the current knowledge on PFAS soil levels in Switzerland. In addition, it sheds light on the PFAS distribution within soil, on most relevant PFAS sources, and on patterns associated with different PFAS uses. These results are very useful for improving our understanding of the concentration of PFASs in soil and will be a relevant contribution to the derivation of soil threshold values in Switzerland.

[1] B. Thalmann, C. Hofer, D. Wächter, B. Kulli, Altlasten Spektrum, 2022, 31 (6), 176-179