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Regional and Nearfield Per- and Polyfluoroalkyl Substances (PFASs) in Ambient Fine Aerosol (PM2.5) in North Carolina, USA
Jiaqi Zhou, Karsten Baumann, Ralph Mead, Stephen Skrabal, Robert Kieber, Gene Avery, Megumi Shimizu, Mei Sun, Samuel Vance, Wanda Bodnar, Zhenfa Zhang, Leonard Collins, Jason Surratt, BARBARA TURPIN, UNC-Chapel Hill
Abstract Number: 468
Working Group: Aerosol Chemistry
Abstract
Per- and polyfluoroalkyl substances (PFASs), being environmentally persistent, are ubiquitous and have been found globally in groundwater, surface water, crops and wildlife. However, PFASs in air remain poorly understood, especially in the United States (US). Given the existence of a fluoropolymer and specialty chemical manufacturing plant (Chemours) and large military bases, as well as more typical sources of environmental PFAS contamination (e.g., fluorinated fire-fighting foam use, urban waste streams), North Carolina (NC) is a good place to study PFAS. This study measured statewide seasonal PFAS concentrations in ambient fine aerosols (PM2.5) in a one-year field campaign at five NC locations (Fayetteville, Charlotte, Research Triangle Park, Wilmington, and Greenville), and measured nearfield weekly PFAS concentrations in fine aerosols (PM2.5) in a six-month field campaign at two locations close to the Chemours facility in Fayetteville, NC (northeast and southwest, within a few miles). Quartz fiber filter samples were collected and analyzed for 34 targeted PFASs by LC-MS/MS on an AB SCIEX Triple Quad™ 6500 mass spectrometer system. With the exception of perfluoro-n-octanoic acid (PFOA) and perfluoro-1-octanesulfonate (PFOS), statewide ambient quarterly concentrations of all targeted species were <1 pg/m3. All concentrations >1 pg/m3 occurred during Jul.-Sept. Notably, PM2.5 has a short atmospheric lifetime (<2 weeks), and thus, the presence of PFOS in these samples raises questions about their sources, since PFOS production was phased out in US ~20 years ago. Twenty-two PFASs were detected in nearfield samples, with ten PFASs above 1 pg/m3. Upwind and downwind nearfield PFAS concentrations and potential sources/formation mechanisms will be discussed. To our knowledge, this is the first US study to provide insights into regional and nearfield (PM2.5) PFAS concentrations.