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27 results on '"Wallace, M. Ariel Geer"'

6. Characterization of PFAS Air Emissions from Thermal Application of Fluoropolymer Dispersions on Fabrics

Author

Wickersham, Lindsay C., primary, Mattila, James M., additional, Krug, Jonathan D., additional, Jackson, Stephen R., additional, Wallace, M. Ariel Geer, additional, Shields, Erin P., additional, Halliday, Hannah, additional, Li, Emily Y., additional, Liberatore, Hannah K., additional, Farrior, Stanley (Mac), additional, Preston, William, additional, Ryan, Jeffrey V., additional, Lee, Chun-Wai, additional, and Linak, William P., additional

Published
2023
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7. Low temperature destruction of gas-phase per- and polyfluoroalkyl substances using an alumina-based catalyst

Author

Shields, Erin P. and Wallace, M. Ariel Geer

Abstract

Per- and polyfluoroalkyl substances (PFAS) pose a major health and environmental problem. Methods are needed to ensure that PFAS are not released into the environment during their use or disposal. Alumina-based catalysts have been used for the abatement of small perfluorocarbons, e.g. tetrafluoromethane and perfluoropropane, emitted during the silicon etching process. Here, an alumina-based catalyst was tested to determine if these catalysts may facilitate the destruction of gas-phase PFAS. The catalyst was challenged with two nonionic surfactants with eight fluorinated carbons, 8:2 fluorotelomer alcohol and N-Ethyl-N-(2-hydroxyethyl)perfluorooctylsulfonamide. The catalyst helped decrease the temperatures needed for the destruction of the parent PFAS relative to a thermal-only treatment. Temperatures of 200°C were sufficient to destroy the parent PFAS using the catalyst, although a significant number of fluorinated products of incomplete destruction (PIDs) were observed. The PIDs were no longer observed by about 500°C with catalyst treatment. Alumina-based catalysts are a promising PFAS pollution control technology that could eliminate both perfluorocarbons and longer chain PFAS from gas streams. Implications: The release of per- and polyfluoroalkyl substances (PFAS) into the atmosphere can cause problems for human health and the environment. It is critical to reduce and eliminate PFAS emissions from potential sources, such as manufacturers, destruction technologies, and fluoropolymer processing and application sites. Here, an alumina-based catalyst was used to eliminate the emissions of two gas-phase PFAS with eight fully fluorinated carbons. No PFAS were observed in the emissions when the catalyst was at 500°C, lowering the energy requirements for PFAS destruction. This shows that alumina-based catalysts are a promising area for research for PFAS pollution controls and the elimination of PFAS emissions into the atmosphere.

Published
2023
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15. Firefighters’ absorption of PAHs and VOCs during controlled residential fires by job assignment and fire attack tactic

Author

Fent, Kenneth W., primary, Toennis, Christine, additional, Sammons, Deborah, additional, Robertson, Shirley, additional, Bertke, Stephen, additional, Calafat, Antonia M., additional, Pleil, Joachim D., additional, Wallace, M. Ariel Geer, additional, Kerber, Steve, additional, Smith, Denise, additional, and Horn, Gavin P., additional

Published
2019
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23. Detection and analysis of endogenous polar volatile organic compounds (PVOCs) in urine for human exposome research.

Author

O'Lenick, Cassandra R., Pleil, Joachim D., Stiegel, Matthew A., Sobus, Jon R., and Wallace, M. Ariel Geer

Subjects
ENVIRONMENTAL exposure, VOLATILE organic compounds, BIOLOGICAL tags, METABOLITES, GAS chromatography/Mass spectrometry (GC-MS)
Abstract

Background: The human exposome, defined as '...everything that is not the genome', comprises all chemicals in the body interacting with life processes. The exposome drives genes x environment (GxE) interactions that can cause long-term latency and chronic diseases. The exposome constantly changes in response to external exposures and internal metabolism. Different types of compounds are found in different biological media. Objective: Measure polar volatile organic compounds (PVOCs) excreted in urine to document endogenous metabolites and exogenous compounds from environmental exposures. Methods: Use headspace collection and sorbent tube thermal desorption coupled with bench-top gas chromatography-mass spectrometry (GC-MS) for targeted and non-targeted approaches. Identify and categorize PVOCs that may distinguish among healthy and affected individuals. Results: Method is successfully demonstrated to tabulate a series of 28 PVOCs detected in human urine across 120 samples from 28 human subjects. Median concentrations range from below detect to 165 ng/mL. Certain PVOCs have potential health implications. Conclusions: Headspace collection with sorbent tubes is an effective method for documenting PVOCs in urine that are otherwise difficult to measure. This methodology can provide probative information regarding biochemical processes and adverse outcome pathways (AOPs) for toxicity testing. [ABSTRACT FROM AUTHOR]

Published
2019
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26. Detection and analysis of endogenous polar volatile organic compounds (PVOCs) in urine for human exposome research

Author

O’Lenick, Cassandra R., Pleil, Joachim D., Stiegel, Matthew A., Sobus, Jon R., and Wallace, M. Ariel Geer

Abstract

AbstractBackground:The human exposome, defined as ‘…everything that is not the genome’, comprises all chemicals in the body interacting with life processes. The exposome drives genes x environment (GxE) interactions that can cause long-term latency and chronic diseases. The exposome constantly changes in response to external exposures and internal metabolism. Different types of compounds are found in different biological media.Objective:Measure polar volatile organic compounds (PVOCs) excreted in urine to document endogenous metabolites and exogenous compounds from environmental exposures.Methods:Use headspace collection and sorbent tube thermal desorption coupled with bench-top gas chromatography-mass spectrometry (GC-MS) for targeted and non-targeted approaches. Identify and categorize PVOCs that may distinguish among healthy and affected individuals.Results:Method is successfully demonstrated to tabulate a series of 28 PVOCs detected in human urine across 120 samples from 28 human subjects. Median concentrations range from below detect to 165 ng/mL. Certain PVOCs have potential health implications.Conclusions:Headspace collection with sorbent tubes is an effective method for documenting PVOCs in urine that are otherwise difficult to measure. This methodology can provide probative information regarding biochemical processes and adverse outcome pathways (AOPs) for toxicity testing.

Published
2019
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