Our research approach is multidisciplinary, combining analytical isotope geochemistry, quantitative modeling, and ecological fieldwork. Some big questions that we are interested in are as follows.
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1. What are the sources and exposure pathways of essential and deleterious chemicals found in wildlife and humans?
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2. How do living organisms metabolize toxicants? Does the toxicokinetic mechanism vary across species including humans?
3. How do climate and ecological changes influence the exposures of wildlife and humans to contaminants and nutrients?
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CURRENT PROJECTS
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1. Developing novel stable isotope techniques for assessing sources, transport, and fate of PFAS.
Collaborators: Neil Sturchio and Deb Jaisi (U of Delaware).
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We are developing new analytical techniques for measuring the multi-element isotope ratios of targeted PFAS compounds commonly found in aqueous film-forming foam (AFFF) formulations and AFFF-contaminated soils and groundwater.
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2. Assessing the transport, transformation, and fate of PFAS across the land-sea transition.
Collaborators: Holly Michael (U of Delaware), Andrea Tokranov (USGS), Michelle Lorah (USGS), Emily Majcher (USGS).
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We conduct a field-based research project to characterize the distribution, transport, fate, and potential remediation mechanisms from upland to coastal environments, specifically, in two Delaware watersheds with contrasting PFAS point sources and land uses.
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3. Understanding PFAS bioaccumulation in the Delaware Bay
Collaborators: Aaron Carlisle (U of Delaware).
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We assess the levels of PFASs in the marine biota from the Delaware Bay and Inland Bays and investigate how PFAS compounds bioaccumulate in the Delaware marine food web.
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4. Assessing human exposure to PFAS via consuming seafood from Delaware Bay
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We aim to assess the current PFAS exposure profile in marine anglers who frequently catch and consume fish from Delaware Bay and to explore strategies for reducing exposure to PFAS associated with seafood consumption.
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5. Investigating sources and bioaccumulation of mercury (Hg) in Arctic ecosystems using stable mercury isotopes
Collaborators: Lisa Loseto (Fisheries and Oceans Canada)
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We use stable Hg isotopes to improve our understanding of present-day environmental sources and bioaccumulation mechanisms of Hg in two distinct arctic ecosystems – Bering Sea vs. Beaufort Sea.
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Orbitrap instrumental setup with direct infusion and electrospray ionization. Graph from Neubauer et al. 2018.
From left to right: Ashley Pavia, Shannon Jones, and Mi-Ling Li conducted fieldwork in St. Jones Reserve, a saltmarsh in the Delaware coast.
Shannon Jones (left) and Tim Smoot (right) were sampling bivalves in Inland Bay, Delaware.
Wix image: Recreational fishing.
Wix image: Arctic ocean.