Date Thesis Awarded
4-2022
Access Type
Honors Thesis -- Access Restricted On-Campus Only
Degree Name
Bachelors of Science (BS)
Department
Geology
Advisor
James Kaste
Committee Members
Nicholas Balascio
Randolph Chambers
Abstract
Heavy metal pollutants can have disastrous effects on human health and surrounding wildlife. Understanding how historical trends align with environmental heavy metal deposition is crucial to predict the health of surrounding ecosystems and the general population. In order to identify shifts in contaminant deposition, I measured trends in Zn, Pb, Cd, and Hg using piston lake core samples. These data suggest that much of the Pb, Cd, and Hg pollutants are deposited atmospherically from regional smelting and industrial processes. I identified recent zinc levels as cause for concern. The prevalent hypothesis in primary literature is that Zn enters watersheds through tire and road wear particles (TRWPs). I sought to determine the chemical speciation of Zn. Through ICP spectroscopy, scanning electron microscopy, and density separations, I determined that TRWPs did not make a significant contribution to increasing Zn levels in Lake Matoaka’s watershed. This undermines the conclusions of previous literature, indicating that there is another source of Zn in the watershed that remains undiscovered. Based on historical trend data as well as my knowledge of current practices in the area, I concluded that this elevated zinc deposition is most likely a combination of atmospheric deposition from smelting processes as well as local construction.
Recommended Citation
Parthasarthy, Rachel, "Developing a Comprehensive 300-year Record of Contaminant Shifts in Lake Matoaka, Virginia" (2022). Undergraduate Honors Theses. William & Mary. Paper 1860.
https://scholarworks.wm.edu/honorstheses/1860
