Chase Holton, Ph.D. is an environmental engineer with Jacobs in Denver, Colorado. He specializes in contaminant fate and transport, including the assessment and mitigation of vapor intrusion (VI) pathway. Chase has been an invited speaker at multiple USEPA VI workshops and has also presented on vapor intrusion at various other national conferences. He is currently involved with a number of ongoing VI research projects for USEPA, DoD, and academia.
Are Per- and Polyfluoroalkyl Substances (PFAS) a Vapor Intrusion Concern?
Research studies, as well as site investigations, over the past several years have provided a glimpse at the extent of PFAS contamination in the environment but have largely overlooked vapor-phase transport. The primary focus of these studies has been evaluating groundwater contamination and impacts to drinking water supplies. As more is learned about the transport of PFAS in groundwater systems, as well as the unique physical and chemical properties of these chemicals, it has become clear that other transport pathways need to be evaluated. Currently, little is known about the volatility and vapor-phase transport of PFAS in the subsurface and whether they pose a vapor intrusion (VI) concern. This review will provide a comparison of the physical and chemical properties of various PFAS compounds, with a focus on those found in indoor and outdoor air. This review will also discuss site and remedial scenarios where vapor-phase transport may be significant.