Looking for available data on the fate and ecotoxicological effects of perfluoroalkylated (PFAS) compounds in terrestrial ecosystems
Résumé
Poly- and perfluoroalkylated substances (PFAS) form a family of over 4000 molecules used in a wide range of industrial, agricultural and domestic applications. Most of these substances are toxic, persistent in the environment and bioaccumulative. Soil plays a key role in the fate of these molecules, delaying their arrival in aquifers but also leading them to be absorbed by the organisms living there. However, the fate and ecotoxicological effects of the vast majority of these compounds in terrestrial ecosystems are poorly understood. Therefore, the objective of this work was to review the fate (mobility, persistence) of PFAS in soils and their effects on terrestrial organisms. Two main queries focused on “fate” and “effects” were defined: they included several keywords related to PFAS, soil, sorption, mobility persistence, degradation, invertebrates, microorganisms, plants, etc. The literature search was done in the Web of ScienceTM. A total of 875 papers was obtained. Two hundred and eighty-nine different PFAS were studied in these papers, belonging to two categories: the perfluoroalkyl acids (PFAA) and their precursors. The most encountered chemical families were perfluoroalkyl carboxylic acids (PFCA) and perflurooctane sulfonic acids (PFSA). Among the 875 papers, 235 allowed to get data related to the fate of PFAS in soils while only 40 papers contained data related to their ecotoxicological effects. We then looked for endpoints such as sorption coefficients (Kd, Kf, Koc), degradation half-life (DT50), median effective concentration (EC50), median lethal concentration (LC50) and bioconcentration factor (BSAF, BAF). Overall, the number of available data was low. Significantly more data were found for sorption than for degradation. Regarding the ecotoxicity, most of the results focused on the model species of earthworm Eisenia fetida and were related to LC50 and bioconcentration. We identified a critical need for more research to characterize the fate of PFAS in soils and their effects on terrestrial organisms.
This work is part of the IPANEMA (Impacts of PFAS: fate and ecotoxicity of mixtures) project funded by ADEME.