Kaylin Xu ’22, Chemistry

Kaylin Xu ’22

Major

Chemistry

Project Title

Investigating the Use of Teeth as Biomarkers for Exposure to Inorganic Pollutants

Certificate(s): French Language and Culture, Materials Science and Engineering, Urban Studies

Current methods assessing exposure to inorganic pollutants, such as blood analysis, are costly and detect only recent exposure. Inorganic pollutants substitute into mineralized body tissues such as bone and teeth, where they can remain for decades. Such hard tissues, particularly deciduous (or baby) teeth, offer a promising avenue of screening people for past long-term exposure to inorganic pollutants. Assessing arsenic and zinc was of particular interest to me, as I was building on previous work in the Myneni Group on arsenic in ancient Mayan remains and zinc in teeth samples from Bangladesh. I conducted literature reviews about arsenic metabolism, teeth nucleation and the in-vitro simulation of teeth nucleation. I learned how to use two thermodynamic codes, MINTEQ and Geochemist’s WorkBench. I modified their thermodynamic databases by adding new minerals from the literature and updating solubility constants. Using those edited codes, I was able to thermodynamically model the arsenic and zinc solids that could precipitate in human teeth at various physiological ranges of different ions. I also had the opportunity to contribute to writing a scientific manuscript. Because I deeply enjoyed this internship, I feel motivated to seek a research-related career in a field related to the environment and sustainability.