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The Spatial Distribution of Particles from Little Cigar Smoke Deposited in Rat Lungs
KAISEN LIN, Christopher Wallis, Emily Wong, Patricia Edwards, Laura Van Winkle, Bahman Asgharian, Anthony S. Wexler, University of California, Davis
Abstract Number: 146
Working Group: Health-Related Aerosols
Abstract
Quantifying the dose of tobacco smoke and the location of this dose in the lung system is important in understanding its toxicity, addiction, and health effects. Several studies have reported contradictory results, i.e. heterogeneous vs. homogenous lobar deposition of inhaled particles, in animal models. However, not many studies have investigated the pulmonary spatial distribution of inhaled particles from tobacco smoke. Even fewer explored the particle size distribution of smoke from little cigars, the total amount of dose, and the lobar deposition of particles. Given the increasing popularity of little cigars, especially in young populations, there is an urgent need to conduct research and collect data on this topic. In our study, we explored the local deposition of particles from combusted Swisher Sweets regular and menthol-flavored little cigar in rat lungs. We exposed 12-week male and female Sprague-Dawley to particles at a mass concentration of 100 mg/m3 for 1 hour. Rats were sacrificed immediately after the exposure and lungs were separated to collect lobe samples. The levels of trace metals, which serve as markers for particle deposition, were quantified with ICP-MS in a lobe-to-lobe resolution. The lobar distribution of deposited particles was determined by comparing the wet mass normalized trace metal concentrations across lobes. To determine the hotspots of deposited particles within each lobe, we will utilize CytoViva hyperspectral microscopy to collect high-resolution data and map particle deposition. The results from this study will also be used to validate and improve the MPPD model, and predict the smoke dose in human lungs.