ERA

Download the full-sized PDF of Human Exposure Sources and Disposition of Perfluoroalkyl Acid IsomersDownload the full-sized PDF

Analytics

Share

Permanent link (DOI): https://doi.org/10.7939/R3SF2MM17

Download

Export to: EndNote  |  Zotero  |  Mendeley

Communities

This file is in the following communities:

Graduate Studies and Research, Faculty of

Collections

This file is in the following collections:

Theses and Dissertations

Human Exposure Sources and Disposition of Perfluoroalkyl Acid Isomers Open Access

Descriptions

Other title
Subject/Keyword
perfluoroalkyl acids
Perfluorooctanoic acid
Perfluorooctane sulfonate
Type of item
Thesis
Degree grantor
University of Alberta
Author or creator
Beesoon,Sanjay
Supervisor and department
Dr Jonathan W Martin
Examining committee member and department
Dr Bernadette Quemerais; University of Alberta, Department of Preventive Medicine
Dr. X. Chris Le; University of Alberta, Department of Laboratory Medicine and Pathology
Dr. Kurunthachalam Kannan; Department of Environmental Health Sciences, School of Public Health, State University of New York, USA
Dr Monika Keelan; University of Alberta, Department of Laboratory Medicine and Pathology
Dr. Steve Hrudey; University of Alberta, Department of Laboratory Medicine and Pathology
Department
Medical Sciences- Laboratory Medicine and Pathology
Specialization

Date accepted
2014-01-14T14:59:58Z
Graduation date
2014-06
Degree
Doctor of Philosophy
Degree level
Doctoral
Abstract
Perfluoroalkyl acids (PFAAs) are a family of emerging toxicants that are non-biodegradable, and have the potential to bioconcentrate and biomagnify. In an attempt to answer questions about human exposure to PFAAs, and subsequent human disposition of these compounds which have public health implications, four hypothesis-driven and multidisciplinary research projects were conducted. The first project used an isomer-specific LC-MS/MS method to characterize the PFAA isomer signatures in house dust, and whether PFAA isomers could cross the human placenta to different extents. The findings showed that a Canadian population was currently exposed to a mix of both telomer and electrochemical perfluorooctanoate (PFOA), despite the latter having been phased out since 2002. Strong evidence for the preferential transfer of branched perfluorooctanesulfonate (PFOS) and PFOA isomers, compared to linear, was found by comparing 20-paired maternal and cord blood samples. The second project was conducted on a local family of seven individuals, all of whom had exceptionally high serum levels of perfluorohexanesulfonate (PFHxS). A forensic investigation was conducted in the family’s dwelling, and data revealed that the source of the high exposure in this family was the house carpets which had been treated multiple times with Scotchgard™ formulations over a period of 15 years. The pathway of exposure was most-likely through inhalation and ingestion of house dust. A series of in vitro experiments were conducted in a third project to assess the dissociation constants (Kd) of linear and branched PFOA and PFOA isomers. Kd’s of the linear isomers were lower than the branched isomers, and in technical mixtures spiked to serum it was evident that the branched isomers were less bound to serum protein, and thus would be more bioavailable to cross into fetal circulation or be excreted by the kidney. The last research project modeled the transplacental transfer of PFAAs in-vitro using cultured human placental syncytiotrophoblasts. This model confirmed the findings of the first study, to the effect that branched isomers, especially in the case of PFOA, crossed the placental barrier more efficiently than linear molecules, independent of their serum protein binding. Overall, this thesis contributed unique observations from biomonitoring of PFAAs at the isomer-specific level, and follow-up experiments helped to explain these while furthermore contributing to our understanding of how PFAAs are biopersistent in humans.
Language
English
DOI
doi:10.7939/R3SF2MM17
Rights
Permission is hereby granted to the University of Alberta Libraries to reproduce single copies of this thesis and to lend or sell such copies for private, scholarly or scientific research purposes only. Where the thesis is converted to, or otherwise made available in digital form, the University of Alberta will advise potential users of the thesis of these terms. The author reserves all other publication and other rights in association with the copyright in the thesis and, except as herein before provided, neither the thesis nor any substantial portion thereof may be printed or otherwise reproduced in any material form whatsoever without the author's prior written permission.
Citation for previous publication
Beesoon S, Genuis SJ, Benskin JP, Martin JW. 2012. Exceptionally High Serum Concentrations of Perfluorohexane Sulfonate in a Canadian Family Linked to Home Carpet Treatment Applications. Environmental Science and Technology. 46:12960-12967Beesoon S, Webster G, Shoeib M, Harner T, Benskin JP, Martin JW. 2011. Isomer profiles of perfluorochemicals in matched maternal, cord and house dust samples: manufacturing sources and transplacental transfer. Environmental Health Perspectives. Nov; 119(11):1659-64.

File Details

Date Uploaded
Date Modified
2014-06-15T07:01:28.581+00:00
Audit Status
Audits have not yet been run on this file.
Characterization
File format: pdf (Portable Document Format)
Mime type: application/pdf
File size: 3673851
Last modified: 2015:10:12 14:44:22-06:00
Filename: Beesoon_Sanjay_April 2014.pdf
Original checksum: d65bc6be998be6f0e0aca25deb8f2120
Well formed: true
Valid: true
Status message: Too many fonts to report; some fonts omitted. Total fonts = 1070
File author: FoMD
Page count: 285
File language: en-CA
Activity of users you follow
User Activity Date