Advancing the Environmental Forensics of Per- and Polyfluoroalkyl Substances

Per- and polyfluoroalkyl substances (PFAS) have impacted drinking water sources in the US and across the globe, resulting in human exposure to PFAS. Understanding the various sources of PFAS within watersheds is a current challenge. Forensics becomes important when seeking remedial strategies or compensation for adverse chemical impacts to properties and human populations, such as those associated with PFAS. While the discipline of environmental forensics is well developed for some classes of contaminants, the environmental forensics of PFAS is in its nascent stage. Chemical ‘fingerprints’ measured by high-resolution mass spectrometry are key to characterizing PFAS sources. Known PFAS sources characterized for this project include groundwater impacted by aqueous film forming foams (AFFF), biosolids leachate, landfill leachates, and various wastewater treatment plant effluents, including those from municipalities and industries. The first step was to determine the chemical fingerprint of each of these sources. The second step was to couple the high- resolution datasets with advanced machine learning to differentiate PFAS sources that can impact surface waters within a watershed. The next steps toward the development of environmental PFAS forensics will also be discussed.