Detection of PFAS in traditional foods: Manoomin (wild rice) and Psiŋčiŋča (arrowhead) across Indigenous land in the Great Lakes region

Per- and poly-fluoroalkyl substances (PFAS) present a significant challenge for human, wildlife, and environmental health due to their persistence and bioaccumulative tendencies. Despite growing public concern, information on PFAS in many plants and animals is relatively limited. This information gap includes species harvested for human consumption and traditional Indigenous foods. As PFAS contamination may pose disproportionate risks to Indigenous food sovereignty and lifeways, understanding the potential presence of these contaminants in traditional foods is crucially important. Seeking to address the information gap, this Tribally driven study analyzed PFAS in two species of aquatic plants: Manoomin (Zizania palustris) and Psiŋčiŋča (Sagittaria latifolia). Found across the Great Lakes region, these plants have both ecological importance and cultural significance for Indigenous peoples. In Psiŋčiŋča, no PFAS were detected above the minimum level of detection (LOD). In Manoomin, four PFAS (perfluoro(2-ethoxyethane) sulfonic acid (PFEESA), perfluorohexane sulfonic acid (PFHxS), perfluorooctane sulfonic acid (PFOS), perfluoro-n-pentanoic acid (PFPeA) were detected in varied plant tissues (roots, stalks, and seeds). All PFAS were detected at levels below 2 ng/g that are unlikely to pose a risk for human consumption at this time. This study is the first to investigate PFAS bioaccumulation in Manoomin or Psiŋčiŋča and quantifies PFAS in surrounding environmental matrices (sediment and surface water). These findings highlight potential exposure pathways for harvesters and can help to inform Tribal food sovereignty initiatives. This study establishes a foundation for future research exploring the impacts of PFAS on the health of Manoomin, Psiŋčiŋča, and the overall condition of aquatic ecosystems.