Abstract View
Exploring the Regional-scale Atmospheric Fate and Transport of Per- and Polyfluoroalkyl Substances (PFAS)
EMMA D'AMBRO, Havala Pye, Chris Allen, Kevin Talgo, Lara Reynolds, Kathy Brehme, Robert Gilliam, Jesse Bash, Benjamin Murphy, Environmental Protection Agency
Abstract Number: 112
Working Group: Carbonaceous Aerosol
Abstract
Per- and polyfluoroalkyl substances (PFAS) are a class of man-made compounds whose emissions to air may contribute, via transport and deposition, to concentrations in surface water, ground water, and private well water in the vicinity of large point sources. Air quality modeling techniques can be used to quantify air concentrations and deposition fluxes to help parse the role of exposure pathways such as direct inhalation and ingestion via contaminated water. We apply the Community Multiscale Air Quality model (CMAQ) version 5.3.1 to a case study in Eastern North Carolina to model the PFAS emissions and transport at fine scale (1 km) from the Chemours Inc. Fayetteville-Works. The 23 PFAS with the largest emissions by mass are identified and added explicitly to CMAQ, along with an aggregate “other PFAS” species to represent the balance of the emissions. An updated deposition parameterization (Surface Tiled Aerosol and Gaseous Exchange, STAGE) is utilized along with estimated chemical properties for each species to simulate the deposition flux to specific, sub-grid land surface types. Thus, the updated model (CMAQ-PFAS) captures the dynamic transformations and removal processes that affect the extent of atmospheric transport of PFAS. We evaluate model performance against deposition sampling and quantify the model uncertainty with these measurements. Different emissions scenarios and species lumping configurations are explored to bound the model behavior and determine the level of detail required to accurately model emissions from other facilities. Our results are an important step in understanding the behavior of significant PFAS emissions from a point source, and can be used to inform studies quantifying exposure and biological effects.
Disclaimer: The views expressed in this presentation are those of the authors and do not necessarily reflect the views or policies of the U.S. EPA.