Superfund Research Program
Measuring Chronic Exposure to and Bioavailability of Organic Chemicals and their Metabolites with a Novel Universal Passive Sampling Device
Project Leader: Damian Shea (North Carolina State University)
Grant Number: P42ES005948
Funding Period: 2011-2018
- Project Summary
Project Summary (2011-2018)
This research addresses the broad SRP theme of Detection Research and more specifically the development of passive samplers for multi-chemical detection and determination of the degree of bioavailability in water and sediment. The first Aim of this research is to develop a universal passive sampling device (PSD) for measuring the time-weighted-average chronic exposure to hundreds of organic chemicals in water. Dr. Shea is advancing the theory, design, and application of PSDs to a very broad range of physico-chemical properties (e.g., KOW = 0-9) so that nearly every organic chemical on the Superfund Priority List of Chemicals, and many of their metabolites, will be sampled by a single PSD. He hypothesizes that a mixed-polymer sorptive phase contained within a non-selective and highly porous membrane will allow linear uptake of nearly all organic chemicals.
In the second Aim of this research, Dr. Shea is establishing the use of PSDs to measure the bioavailable fraction of PCBs and PCB metabolites in water, sediment, and soil. He is conducting laboratory bioavailability experiments with PCB-contaminated soil, sediment and water to advance scientific understanding of the mechanisms controlling PCB bioavailability and perform field verification at NPL sites. In collaboration with Dr. Swenberg, Dr. Shea is using extracts of his samples to determine the relationship of his bioavailability measure to the dioxin toxic equivalency factor response in Dr. Swenberg's cell assays.
Under the third Aim, Dr. Shea is establishishing the use of PSDs to measure the bioavailable fraction of PAHs and PAH metabolites in water, sediment, and soil. In collaboration with Dr. Aitken, he is performing studies very similar to those in Aim 2 to develop the use of PSDs to measure PAH and PAH metabolite bioavailability under both controlled laboratory conditions and at NPL sites. This work is advancing understanding of and ability to measure the partitioning of PAHs and metabolites among dissolved organic carbon, soft and hard (soot) particulate carbon, weathered oil/oil product phases, and biota. Dr. Shea hypothesizes that his novel PSD design will provide an accurate measure of bioavailable chronic exposure under a broad range of conditions and that PSD-derived data will overcome a critical barrier to more accurate estimates of bioavailability and risk.