Project Summary (2017-2022)

This University of Rhode Island-led Sources, Transport, Exposure and Effects of PFASs (STEEP) Superfund Research Program Center project is developing, validating and deploying novel passive samplers for the detection of poly- and perfluoroalkyl substances (PFASs) in water and porewater. At contaminated sites, as the extent of a PFAS plume is investigated, active water sampling is labor- and time-intensive, prone to sampling/contamination artifacts and does not necessarily reflect typical conditions. The benefits of field-validated passive sampling approaches include (i) ease of handling; (ii) ease of shipping to/from sampling sites; (iii) ease of analysis without time-consuming extractions; (iv) reduced potential for contamination; and (v) lower detection limits that will be needed as regulatory agencies adjust their references doses.

This project focuses on three innovative research components, consisting of the development and field validation of three novel detection tools: (i) developing the PFAS porewater fiber for measuring PFAS concentrations in porewater to deduce partitioning and bioavailability, and comparing results to those from controlled bioaccumulation tests for PFAS accumulation in bivalves, in collaboration with the U.S. Environmental Protection Agency (EPA); (ii) field validating a PFAS sampling tube for reporting time weighted average (TWA) concentrations in water, and (iii) validating a passive polyethylene PFAS precursor sampler for reporting precursor concentrations.

Preliminary results indicate that the PFAS sampling tube functions as a diffusive sampler, implying that the uptake of PFASs depends on their molecular diffusivity, not on the water flow outside of the sampler tube. Once PFAS diffusivities are characterized by this project, water concentrations of PFASs can easily be derived. The partitioning of non-ionic PFAS precursors into the polyethylene sampler follows predictions based on hexadecane-water partitioning, and that polyethylene samplers accumulate PFASs in surface waters.

This project is well-integrated within STEEP. Sites for field validation and application are located on Cape Cod, MA, the primary site of the STEEP Community Engagement Core activities. Researchers are engaging residents and stakeholders to address concerns about long-range PFAS transport and characterizing the extent of impacted ponds, creeks and estuaries. The research team works closely with the Exposure Assessment and Chemometrics of PFASs project through common field deployments of passive samplers in ponds near Joint Base Cape Cod, where groundwater is contaminated by aqueous film forming foams, and works with the PFAS Compound Effects on Metabolic Abnormalities in Rodents project on tissue analysis and characterizing basic properties for PFASs. Lastly, researchers work with the Research Translation Core and U.S. EPA to translate results and applications of passive samplers for PFASs to state and federal agencies, and with the Training Core on lectures (detection, sampling), laboratory activities (detection, QA/QC) and field trips (deployment, sampling).