Summary
Introduction:
This text summarizes a scientific study that analyzes the exposure and toxicology of e-cigarette vapors using different puffing behaviors. The study uses a coupled physiologically based pharmacokinetic (PBPK) – computational fluid dynamics (CFD) model with a numerical respiratory tract model. The study aims to develop a numerical prediction method to assess human health risks caused by the inhalation of various contaminants generated by e-cigarettes.
Key Points:
* The study used a numerical respiratory tract model, including the oral cavity, pharynx, larynx, trachea, and bronchial tubes.
* Two types of puffing profiles were prepared based on measurement data from Vansickel et al.
* The PBPK – CFD model was constructed by Tian and Longest (2010) and applied to the numerical respiratory tract model.
* The study focused on formaldehyde, acetaldehyde, acrolein, benzene, toluene, glycerol, and nicotine as representative contaminants.
* The convection and diffusion of the contaminants in the airway were analyzed using CFD, while their absorption/diffusive transport, metabolic clearance, and elimination in the respiratory tissue were predicted by the PBPK model.
* The study indicated the total fractions of contaminants inhaled from e-cigarette, including those adsorbed onto tissue surface, transported to deeper bronchial regions, and released into the indoor environment by exhalation.
* The long puffing behavior leads to elevated contaminants uptakes in the respiratory tract model compared to the short puffing behavior.
Main Message:
The study highlights the importance of analyzing the comparative health impact caused by e-cigarette smoking with different puffing behaviors. The study demonstrates that the long puffing behavior leads to higher total adsorption of contaminants than the short puffing behavior. The findings suggest that the prediction of dynamics of various chemicals in the air and tissue phases of the respiratory tract is essential for quantitative and reasonable inhalation exposure assessments. Therefore, coupled PBPK – CFD analyses should be developed to predict the dynamics of different chemical contaminants in the respiratory tract. Overall, the study emphasizes the need for further research to assess the human health risks associated with e-cigarette smoking.
Citation
Kuga K, Ito K. Comparative inhalation exposure/toxicology analysis of e-cigarette vapors with different puffing behaviors using PBPK-CSP-CFD approach. IOP Conf Ser: Mater Sci Eng. 2019;609:042004. doi:10.1088/1757-899x/609/4/042004
