PHYTOSCREENING FOR PER- AND POLYFLUOROALKYL SUBSTANCES (PFAS) NEAR FORT GEORGE G. MEADE

Abstract

Per- and polyfluoroalkyl substances (PFASs) are a class of contaminants with growing concerns regarding their toxicity to humans, their high persistence, and their ubiquity in the environment. Many U.S. military bases that historically used PFAS-based Aqueous Film-Forming Foams (AFFFs) are now being investigated by the U.S. Department of Defense (DOD) to address potential releases into the environment, especially into groundwater. This study explores a preliminary screening approach to delineate the plume of groundwater contamination—phytoscreening—which uses the analysis of plant tissue to detect subsurface contamination. For phytoscreening applications, this study evaluated three tree species: red maple (Acer rubrum), sweetgum (Liquidambar styraciflua), and willow oak (Quercus phellos). Sites were selected in proximity to a point source, Fort George G. Meade, in MD, USA. At each tree, samples were collected from the leaves, twigs, trunk (n=54, 9 trees), and soil surface (0-10 cm) (n=18) to characterize PFAS accumulation between each plant tissue. A linear mixed effects model with censored data (LMEC) was used to analyze the effects of species and plant tissue. Of the 15 compounds detected in groundwater at Fort Meade, red maple and willow oak captured 7 compounds each, while sweetgum captured 3. Red maple and willow oak accumulated higher ∑27PFAS concentrations than sweetgum. PFAS accumulation also varied by plant tissue, with twigs showing the highest concentrations, followed by the trunk, and then leaf. Results indicate that the plant species and tissue type play a critical role in the accumulation of PFAS in trees.