Post-wildfire soil and aquifer contamination: A review

Abstract

The need to understand the effects of wildfire and post-fire contamination of soil and groundwater has grown as a result of the expansion of the extent and severity of wildfires around the world. In addition to their direct hazards, wildfires can also contribute to human and environmental health concerns due to secondary contamination, e.g., wildfire suppression such as aqueous film-forming foams (AFFF) can release perand polyfluoroalkyl substances (PFAS) into the soil, which are very mobile, toxic, and persistent. Both direct seepage through the topsoil and biotransformation of fluorotelomers (FTs) determine the fate of PFAS in soils and aquifers. Research has indicated that phase partitioning behavior, such as sorption to soils and sediments, controls the fate and transport of chemicals in the environment According to various studies, the main soil or sediment characteristics that control PFAS’ sorption behavior include organic carbon (OC), pH, index cations, and ionic strength. However, neither OC, pH, nor claycontent alone could explain the sorption behavior of PFAS. More research is needed to help to understand the role of co-contaminants on the sorption behavior of PFAS, the role of surface charge on the sorption of PFAS, and on a wider range of PFAS chain compounds in the future. This paper aims to review the fate and transport of PFAS and identify the areas of research need.