Detection of PFAS in sugarbushes across the Ceded Territories: a method for PFAS analysis in maple sap and syrup

Per- and poly-fluoroalkyl substances (PFAS) pose significant health and environmental risks due to their persistence and potential for bioaccumulation. Using a new analytical method, we quantified PFAS in maple sap and syrup from Indigenous lands in the Ceded Territories, a largely under-surveyed area. Our investigation focuses on maple products due to their cultural significance to Ojibwe communities, and economic importance as harvestable resources. We detected two PFAS (PFBA and PFPeA) in maple sap, and ten PFAS (8:2 FTSA, N-EtFOSE, N-MeFOSE, PFBA, PFBS, PFDoA, PFHxA, PFOA, PFPeA, and PFTeDA) in maple syrup at low concentrations that do not presently pose an immediate health risk for human consumption in this area. This study is the first to detect PFAS in both maple sap and syrup, demonstrating the efficacy of an adapted analytical method with low detection limits (> 1 ng/L) for a broad range of PFAS compounds. This method represents a novel application of established techniques to test previously unstudied matrices. Indigenous herbalists encourage paying close attention to plants, as they offer valuable insight into environmental well-being, including the presence of contamination. Given that maple sap and syrup reflect environmental contamination from various sources including rainwater, groundwater, porous water, and soil, we propose that maple trees can be used as a biomonitoring system for PFAS across a forested area. This tribally driven approach can help assess ecosystem health and evaluate potential human health risk associated with PFAS contamination in maple products.