Date of Award

2025

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Biotechnology Science and Engineering

Committee Chair

Luis R. Cruz-Vera

Committee Member

Emanuel A. Waddell

Committee Member

Bradley R. Kraemer

Committee Member

Joseph D. Ng

Committee Member

Jeffrey J. Weimer

Committee Member

Tingting Wu

Research Advisor

Luis R. Cruz-Vera

Subject(s)

Manganese--Toxicology, Drinking water--Manganese content--Measurement, Movement disorders, Spectrophotometric test method

Abstract

Manganism, a neurotoxic disease from the hyperaccumulation of manganese, follows an etiology that parallels Parkinsonism. Non-occupational Manganism is acquired by the lifelong accumulation of manganese through water contaminated by natural and industrial sources. Biologically active manganese (II) eludes flocculation and filtration removal methods at water utilities. The U.S. Standard Methods For the Examination of Water and Wastewater persulfate testing method uses mercury sulfate, concentrated nitric and phosphoric acids, silver nitrate, and ammonium persulfate. The low detection limit of 210 µg/L is an order of magnitude greater than the World Health Organization (WHO) allowable limit of 10-50 µg/L. In 2004, the EPA chose not to adopt the WHO inclusion of manganese monitoring as a primary drinking water contaminant. They established a limit of 300 µg/L as a “health advisory” and 50 µg/L as an “aesthetic standard” to prevent staining, bad taste, and smell from the water. These limits are voluntary because manganese is a secondary drinking water contaminant where routine testing is not required. The Global International Standard ISO Method 6333 utilizes formaldoxime, a chemical not approved for use in the U.S. by the American National Standards Institute (ANSI). To address the need for a safer, greener, and compliant testing method, reagents were synthesized, characterized, and used to develop a spectrophotometric quantitative testing method that spans the full compliance range established by WHO. This low-cost testing method enables on-site monitoring at water utilities, obviating the need for costly outsourced testing. Manganese can become a primary drinking water contaminant, with utilities testing daily and taking preventative action to toxic exposure before water release, rather than reporting after a harmful event. Manganese, as a trace metallomics requirement in all biological systems, is presented herein, and why too much of a good thing manifests as neurological pathologies. Modes of toxicity in humans are discussed as occupational and non-occupational sources. The history of Manganism, from its discovery in 1837 to the current day, is presented with manganese toxicity sources within each appropriate section. Legislative policies that are currently outdated can be reviewed and revised utilizing these metrics.

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