The topic of per- and polyfluoroalkyl substances (PFAS) is a late-breaking issue due to its high environmental relevance (toxicity, persistence and bio accumulation) and due to the detection of PFAS as contaminants in various environmental compartments including groundwater, surface water and soil. PFAS enter the environment via different pathways such as industrial, agricultural, and house-hold activities but as well through firefighting activities using aqueous fire-fighting foams (AFFF) which contain a high variety of PFAS molecules. Especially firefighting training zones are therefore highly exposed to PFAS contamination in soil and ground water and can even pollute other regions since PFAS can be carried away from the source within the soil pore water.Previous studies have shown that the transport and retention of PFAS in soils depend on various factors such as the PFAS type (e.g. molecular structure and carbon chain length), the soil properties (e.g. amount of organic carbon, surface charge), and the pore water (e.g. degree of saturation, pH). Still, the retention and release mechanisms of PFAS on soil constituents are not completely elucidated, and an official, universal protocol for the determination of PFAS concentrations in the subsoil is not existing yet.PFAS are commonly analyzed in the ground water or/and in the soil assuming that PFAS transport only occurs directly by desorption into solution and not considering the co-transport due to strong adsorption of PFAS to eroded particles as a possible solid carrier phase next to the liquid phase. Still, this assumption might not be correct including the already observed spatial and temporal interactions between the soil and the soil pore water like e.g. soil particle mobilization caused by wetting and drying cycles or macro pore flow. Especially with regard to the surfactant characteristic of PFAS, particle mediated transport of PFAS should be further investigated since only few projects on this topic have been carried out so far. Based on the findings of enhanced leaching of one PFAS molecule because of its adsorption to released particles in artificially contaminated, homogenously compacted soil columns, we now increased the complexity to more real-life conditions working with undisturbed soil columns from a firefighting training site contaminated by various PFAS through the use of AFFF. We expose these columns to simulated rain falls of different rain intensities and dry periods and afterwards analyze the drained effluent water for PFAS once in the liquid phase and once adsorbed to eroded soil particles. In preliminary tests we were already able to detect even long-chain PFAS in the collected leachate (although their mobility in soil is expected to be low) which could be attributed to colloid leaching and colloidal particles as a carrier phase for long-chain PFAS.The separated analysis of PFAS in the liquid and the solid phase will help us to better understand the contribution of soil particles to the transport of PFAS in the soil pore water and therefore possibly point out the risk of higher pollutions of remote areas, and whether this contribution should also be taken into account in the determination of PFAS in the subsoil in the future.< Leer menos