ORCID

https://orcid.org/0009-0008-7040-3602

Date of Award

Fall 2024

Language

English

Embargo Period

11-27-2024

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

College/School/Department

Department of Environmental Health Sciences

Program

Environmental Health Sciences

First Advisor

Patrick Parsons

Committee Members

Fernando Barbosa, Sherry Faye, Beth Feingold, Aubrey Galusha, Christopher Palmer

Keywords

mercury speciation, mercury, ICP-MS, biomonitoring

Abstract

Mercury (Hg) exposure from environmental sources and consumer products presents a significant public health concern. The toxicity of methylmercury (MeHg) differs considerably from inorganic mercury (iHg), such that their separation and quantification in whole blood is helpful in identifying sources and possible pathways of exposure. Speciation methods provide a more detailed picture regarding human exposure to toxic mercury species and their effects on human health. This dissertation focuses on advanced analytical techniques for human biomonitoring and clinical diagnosis of Hg exposure. The primary aim of this research is to address important knowledge gaps and analytical challenges in studies of Hg species in whole blood.

A major contribution of this work is the development and validation of a novel, rapid, and robust analytical method for the speciation of MeHg and iHg in whole blood using isocratic liquid chromatography coupled with vapor generation inductively coupled plasma tandem mass spectrometry (LC-VG-ICP-MS/MS). This method, optimized for high-throughput biomonitoring, allows for the quantification of Hg species at population levels. Validation studies demonstrated the method's competitive limits of detection (LODs) compared to gas chromatography-based techniques, making it a promising tool for the analysis of human blood for Hg species.

The validated LC-VG-ICP-MS/MS method was applied to a pilot study involving archived blood samples from the New York City Health and Nutrition Examination Surveys (NYC HANES). Method robustness was assessed by analyzing over 300 samples for the distribution of Hg species collected over a decade, between 2004 and 2013–2014. These findings offer valuable preliminary data for understanding Hg exposure patterns in a NYC population, with implications for future public health biomonitoring studies.

Additionally, the method was employed in two individual case studies. One case focused on suspected exposure to iHg from skin lightening creams, and the other on suspected exposure to MeHg from excessive fish consumption. These case studies revealed detailed information on Hg speciation in blood, contributing to the clinical understanding of mercury poisoning and highlighting the importance of speciation analysis after excessive Hg exposures.

Finally, this dissertation extended the utility of the LC-VG-ICP-MS/MS method to non-biological matrices, such as skin lightening creams, and by integrating X-ray fluorescence (XRF) analysis for pre-analytical screening. The speciation analysis identified iHg contamination in skin lightening creams, many exceeding the FDA's safety limits, highlighting the importance of speciation analysis in ensuring consumer product safety.

License

This work is licensed under the University at Albany Standard Author Agreement.

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