Poster Presentation Society of Environmental Toxicology and Chemistry Australasia 2021

Transfer of Polyfluorinated Phosphate Diesters (diPAPs) in a Plant-Soil System with Maize (Zea Mays) (#179)

René Lämmer 1 , Janine Kowalczyk 2 , Hildegard Just 2 , Jörn Breuer 3 , Bernd Göckener 1 , Matthias Gaßmann 4 , Eva Weidemann 4 , Thorsten Stahl 5 , Mark Bücking 1 6
  1. Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Schmallenberg, Germany
  2. German Federal Institute for Risk Assessment, Berlin, Germany
  3. Unit of Agroecology, Agricultural Technology Centre Augustenberg, Karlsruhe, Germany
  4. Unit for Civil Engineering and Environmental Engineering, University Kassel, Kassel, Germany
  5. Chemisches und Veterinäruntersuchungsamt Münsterland-Emscher-Lippe (CVUA-MEL), Münster, Germany
  6. School of Chemistry, Monash University, Melbourne, Victoria 3800, Australia

The objective of the publicly sponsored project PROSPeCT is the development of scientific basics for the behaviour of per- and polyfluoroalkyl substances (PFAS) based on a contamination site in southwest Germany. The study focusses on the environmental behaviour of 6:2 diPAP and 8:2 diPAP in the pathway from soil to plant. For this purpose, 6:2 diPAP and 8:2 diPAP, respectively, were applied to PFAS free soils. Maize (Zea mays) was planted on all soils. After the vegetation period, all plant compartments and the soils were individually analysed for PFAS contamination. The primarily applied substances made up the majority of PFAS in the soil. Furthermore, perfluorocarboxylic acids (PFCAs) were found in the soil although they were not initially applied. Only PFCAs with chain lengths ≤ C6 (6:2 diPAP application) or chain lengths ≤ C8 (8:2 diPAP application) were detectable in the aboveground plant compartments with perfluoropentanoic acid being the main component in both cases. The highest levels of PFCAs occurred in the leaves, while significantly lower levels were found in the cob and grain in particular. The detection of PFCAs in the soil and in the plant compartments indicates a degradation of diPAPs into persistent PFCAs in the environment. 6:2 diPAP and 8:2 diPAP themselves mainly remain in the soil, whereas the plant takes up notable quantities of PFCAs. Especially leaves and husk accumulate short-chain PFCAs. This shows the potential of diPAPs to contribute to the total PFCA contamination. These results provide important insights into the transfer of PFAS from contaminated soil into plants. As maize plants in particular are used as animal feed, the uptake of PFAS from field soil displays an entry path into the feed and food chain and thus may serve as a pathway for human exposure to PFAS.