Portland State University. Department of Chemistry
Robert M. Strongin
Date of Publication
Doctor of Philosophy (Ph.D.) in Chemistry
Electronic cigarettes, Cigarette smoke -- Composition
1 online resource (viii, 85 pages)
The purported safety of electronic cigarettes has come under scrutiny with the significant increase of lung related illnesses starting in the summer of 2019. Public view has started to shift towards understanding the potential negative health impact associated with these devices. While many investigations indicate probable hazards present in e-cigarette aerosols, inter-laboratory assessments are wide ranging and can be contradictory. Due to the novelty of this field, relatively little is known about these products. In this work, the identification and quantification of inhalation toxicants such as formaldehyde, acrolein, acetaldehyde and dihydroxyacetone are reported. Results of the investigation of the ability of various e-cigarette components to modulate levels of toxins are also described. Upon identifying that inter-device power settings did not correlate well with toxin production, the relationships between wicking efficiency and coil parameters were studied. A simple model was developed that performed in the moderate to substantial range as a predictor of the relative carbonyl levels produced upon vaping twelve different e-cigarettes. It can thus be used to predict the relative harm of devices across varying styles. Related investigations showed that additives in the electronic cigarette liquid promote the formation of toxicants upon aerosolization. The addition of triacetin, an additive found in both e-cigarettes and combustible cigarettes, led to a significant increase in the levels of formaldehyde, acrolein and acetaldehyde. By using 13C labeled triacetin and a combination of 1H NMR and 13C NMR, the ester hydrolysis of triacetin to form acetic acid was identified. The released acetic acid acted as a catalyst to promote the degradation of propylene glycol and glycerol upon heating. Carbon-13 labeling thus enabled the precise identification of the mechanistic pathway whereby triacetin addition to e-liquid leads to elevated levels of aldehyde toxins in e-cigarette aerosols. The elucidation of the physical and chemical origins of e-cigarette aerosol toxins will aid efforts to mitigate harm.
Vreeke, Shawna, "Investigating the Origins of Toxins Present in Electronic Cigarette Aerosols" (2019). Dissertations and Theses. Paper 5338.
Available for download on Thursday, November 19, 2020