Date of Thesis

Spring 2023

Description

Despite the large amount of time that individuals spend indoors during their lives, very little attention was paid to the chemistry that occurs on indoor surfaces until recently. Although not visible to the naked eye, physical and chemical processes, such as partitioning and oxidation, are occurring on virtually every indoor surface in a typical household. Indoor pollutants, ranging from skin oils to environmental cigarette smoke, drive a lot of these processes. The transformation of indoor surfaces by indoor pollutants can increase chemical exposure risks as new irritants or carcinogens can be introduced to the surfaces. In this thesis, I describe a series of studies that used cigarette smoke as a proxy for reactive oxygen species to investigate how surface composition is altered after exposure to an indoor pollutant. Early work on this project focused on designing the smoking apparatus and optimizing experimental methods. After constructing a more controlled system, cigarette smoke was deposited onto glass substrates that were pre-coated with different surface films. The molecules that were present on the surface of the substrate were analyzed at specific time intervals with high-resolution mass spectrometry. Temporal trends of 4 tobacco alkaloids – nicotine, cotinine, N-formylnornicotine, and nicotelline – and nicotine oxide were analyzed over the course of 1 week. The relative changes in these compounds over time were notably different in the presence and absence of a surface film. In the presence of a surface film, the tobacco alkaloids increased, likely in part due to partitioning. Analysis of oleic acid and squalene surface films when exposed to cigarette smoke revealed the formation of multiple oxidation products, many of which shared the same molecular formula. Ongoing analysis is being conducted to propose the chemical structures of these compounds. Future studies will expand this work to encompass the diversity of indoor environments by investigating different types of surface films, surface materials, and sources of reactive oxygen species.

Keywords

cigarette smoke, third-hand smoke, indoor chemistry, indoor surfaces, oxidation, partitioning

Access Type

Honors Thesis

Degree Type

Bachelor of Science

Major

Chemistry

Minor, Emphasis, or Concentration

Biology

First Advisor

Douglas B. Collins

Second Advisor

Timothy G. Strein

Third Advisor

Moria C. Chambers

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