Characterizing the Air Emissions, Transport, and Deposition of Per- and Polyfluoroalkyl Substances from a Fluoropolymer Manufacturing Facility.

ABSTRACT

Per- and polyfluoroalkyl substances (PFASs) have been released into the environment for decades, yet contributions of air emissions to total human exposure, from inhalation and drinking water contamination via deposition, are poorly constrained. The atmospheric transport and fate of a PFAS mixture from a fluoropolymer manufacturing facility in North Carolina were investigated with the Community Multiscale Air Quality (CMAQ) model applied at high resolution (1 km) and extending ∼150 km from the facility. Twenty-six explicit PFAS compounds, including GenX, were added to CMAQ using current best estimates of air emissions and relevant physicochemical properties. The new model, CMAQ-PFAS, predicts that 5% by mass of total emitted PFAS and 2.5% of total GenX are deposited within ∼150 km of the facility, with the remainder transported out. Modeled air concentrations of total GenX and total PFAS around the facility can reach 24.6 and 8500 ng m-3 but decrease to ∼0.1 and ∼10 ng m-3 at 35 km downwind, respectively. We find that compounds with acid functionality have higher deposition due to enhanced water solubility and pH-driven partitioning to aqueous media. To our knowledge, this is the first modeling study of the fate of a comprehensive, chemically resolved suite of PFAS air emissions from a major manufacturing source.