Tracing the movement of electronic cigarette flavor chemicals and nicotine from refill fluids to aerosol, lungs, exhale, and the environment.

Introduction: This manuscript presents a study on the movement of flavor chemicals and nicotine in electronic cigarette (EC) refill fluids, aerosols, and human exhale, and their contribution to EC exhaled aerosol residue (ECEaR). The study aims to provide information useful in regulating EC use.

Key Points:

* The study used two EC refill fluids, "Dewberry Cream" and "Cinnamon Roll," to generate aerosols with varying puff durations and wattages.
* The transfer efficiency of flavor chemicals and nicotine from refill fluids to aerosols was affected by the properties of the chemicals, EC wattage, pump head, puff duration, and puff volume.
* Participants were categorized as "mouth inhalers" or "lung inhalers" based on their exhale of flavor chemicals and nicotine.
* Lung inhalers had a higher retention of flavor chemicals and nicotine compared to mouth inhalers.
* Mouth inhalers contributed to ECEaR, while lung inhalers did not.
* The study also found that cinnamaldehyde was retained better than other flavor chemicals by mouth inhalers, which is concerning due to its potential toxicity.

Main Message: The study highlights the importance of considering EC user topography and the properties of flavor chemicals when assessing the potential health impacts of EC use. The findings can inform regulatory decisions regarding ECs, particularly in relation to ECEaR. The study also underscores the need for further research on the potential health effects of flavor chemicals in EC refill fluids.

Khachatoorian C, McWhirter KJ, Luo W, Pankow JF, Talbot P. Tracing the movement of electronic cigarette flavor chemicals and nicotine from refill fluids to aerosol, lungs, exhale, and the environment. Chemosphere. 2022;286:131494. doi:10.1016/j.chemosphere.2021.131494