Superfund Research Program
Developing and Evaluating Technology to Measure PAH Fate and Exposures
Project Leader: Kim A. Anderson
Grant Number: P42ES016465
Funding Period: 2009-2025
Studies and Results
Specific Aim 1. the researchers have successfully fractionated PSD extracts and have tested for toxicity in each fraction within the zebrafish model. The researchers have successfully reconstituted the PSD fractions and have preserved the original toxicity. The researchers have shown the fractionation manipulations do not impart additional toxicity.
Impact: The researchers have shown that PAHs are not responsible for the toxicity observed at the recently remediated McCormick and Baxter Superfund site (in Oregon).
Specific Aim 2. The researchers have successfully integrated their bioavailable extract into laboratory-based stressors experiments. Real-world mixtures of bioavailable PAHs can be photo-degraded, the researchers have shown that the PSD sequester OPAHs (oxygenated PAHs) from contaminated environments and that OPAHs are formed from PSD mixture extracts after exposure to UVB and finally that these OPAHs are consistent with those measured at weather sites. With a short 30-minute exposure (test conditions consistent with a summer day in North America) the researchers observe up to 40% increase in some OPAH concentrations. Coupling PSDs to UV is a demonstration of a new approach.
Impact: PSD extracts provide chemical mixtures that better reflect site-specific exposure scenarios. Importantly, the approach allows for the identification and quantification of new chemicals. Thus, pairing PSD technologies with UV irradiation may help researchers better characterize changes in chemical exposure on a site-specific basis, allow for identification of non-regulated toxicants characterized by little or no toxicity data, and extend the application of existing mixture toxicity evaluation methods.
Specific Aim 3. The researchers have successfully used passive sampler extracts from Superfund sites to predict resident crayfish tissue concentrations for PAHs.
Impact: Human health and ecological risk assessments are often challenged with insufficient quantities of site-specific biological data. The combined passive sampling and PLS modeling approach described here provides a relatively simple and powerful means to predicting PAH concentrations in recreationally important resident aquatic organisms. This approach may be especially useful during preliminary and screening-level assessments, when site-specific measurements are typically in limited supply.
From grant years 1-4, Specific Aim 1: Further develop environmental exposure bio-analytical measurement technologies capable of quantitatively sequestering bioavailable contaminant concentrations.
The researchers have successfully developed a passive wristband sampler for measuring an individual's exposure to organic chemicals. They have identified PAHs, flame retardants, nicotine, as well as other consumer products, personal care products. The researchers have also tested and develop silicone passives samplers for air, water and sediments. They have tested the stationary samplers in Portland Harbor. The researchers found they were complimentary to the polyethylene samplers routinely used, specifically they were more effective at sequester of semi-polar compounds (with Kow <4.0).
Concentrations from PSDs may be used in air and water exposure cumulative risk assessments as well as substituted for fish/shellfish tissue concentrations in existing health risk models. Adding passive sampler data to assess cumulative exposure and to health risk models increases spatial and temporal precision, improves risk estimates based on environmental characterization of exposure, reduces animal collection, and reduces costs.