Ecotoxicological Effects of Per- and Polyfluoroalkyl Substances (Pfas) on Earthworms and Plants and a New Pfas Adsorbing Organoclay to Immobilize Pfas in Soils

Abstract

A novel adsorptive organoclay (Intraplex AÒ) was developed for the in situ immobilization of per- and polyfluoroalkyl substances (PFAS) in the vadose zone. We provide the first evaluation of the effects of Intraplex AÒ on earthworms and plants in a PFAS-contaminated soil. Ecotoxicological tests were carried out on control soil with and without Intraplex AÒ (C + I and C, respectively) and PFAS-contaminated soil with and without Intraplex AÒ (PFAS + I and PFAS, respectively). We investigated the ecotoxicological effects of PFAS and Intraplex AÒ on the growth, reproduction and survival of earthworms (Eisenia fetida) and on plant growth (oat – Avena sativa and turnip – Brassica rapa L. silvestris). Lower lethality of earthworms was observed in PFAS + I than in PFAS soil. Earthworms avoided both C + I and PFAS + I soils, and reduced earthworms’ reproduction was found in both soils. For both plant species, the PFAS + I soil yielded less fresh and dry shoot biomass than the PFAS soil, while root growth remained unaffected by the presence of Intraplex A®. Soils with Intraplex AÒ had some negative effects on plants and earthworms, which must be balanced with its benefits as an in situ PFAS adsorbent.

Keywords: ecotoxicity, immobilization, Eisenia fetida, Avena sativa, Brassica rapa L.