PROJECT SUMMARY/ABSTRACT – PROJECT 4 DETECTION STEEP II Project 4–Detection and Remediation (P4-Detection), will further develop, validate, field-test and deploy passive sampling tools for per- and polyfluorinated alkyl substances (PFAS) in water, biota, air and dust. The field-validation and applications of passive samplers offer several key advances for the detection of PFAS including (i) assessment of relevant human exposure via time-weighted average concentrations, (ii) aiding in identifying the extent of site contamination, and (iii) remediation via simple adsorbents and reliable monitoring tools that can be deployed before, during, and following remediation to verify success. P4–Detection offers several innovative research components to address knowledge gaps surrounding environmental exposure to legacy and novel PFAS, and to provide novel tools to stakeholders. For example, P4–Detection will develop a simple, but effective filter for PFAS in groundwater, and use its passive samplers to monitor a field-based ex situ remediation trial for PFAS in groundwater on Cape Cod (Aim 1). P4–Detection will simultaneously characterize PFAS bioaccumulation in wildlife and field-test passive samplers in the Delaware River (Aim 2), while using passive samplers to measure the biotransformation and bioaccumulation of PFAS in controlled laboratory exposures. P4–Detection will also contribute unique tools and data on PFAS in outdoor and indoor air, and dust to inform STEEP II’s PFAS exposure assessment (Aim 3). P4–Detection will collaborate with P1–Exposure to assess the importance of atmospheric transport of PFAS, another research gap and significant need for STEEP’s stakeholders (Aim 3). P4–Detection will thereby address the SRP mandates of developing “methods to reduce the amount and toxicity of hazardous substances” and “methods and technologies to detect hazardous substances in the environment.” The work of P4–Detection is well-integrated with the other STEEP II research projects and cores: it will maintain strong links with P1–Exposure, with a joint focus on bioaccumulation, and the use of passive samplers for indoor and outdoor air sampling of PFAS; continue work with P3–Mechanisms on chemical analysis of PFAS and share mixture profiles of PFAS in cell assays and rodent models; work with P2–Critical Effects to assess the contribution of indoor air and dust to PFAS exposure in the Faroe Islands relative to seafood consumption as part of PI Lohmann’s Fulbright Arctic Initiative fellowship; and exchange samples with P1–Exposure to compare the results of extractable organofluorine (EOF) analysis and perform non-target analysis for the other projects. Lastly, P4–Detection will work with STEEP II’s research translation team, states, and U.S. EPA to disseminate results and applications of passive samplers for PFASs to state and federal agencies; with the DMAC on adhering to FAIR data principles and statistical analysis of the results; with the CEC on indoor...