Quantifying the dose and distribution of tobacco smoke in the respiratory system is critical for understanding its toxicity, addiction potential, and health impacts. Epidemiologic studies indicate that the incidence of lung tumors varies across different lung regions, suggesting there may be a heterogeneous deposition of smoke particles leading to greater health risks in specific regions. Despite this, few studies have examined the lobar spatial distribution of inhaled particles from tobacco smoke. This gap in knowledge, coupled with the growing popularity of little cigars among youth, underscores the need for additional research with little cigars. In our study, we analyzed the lobar deposition in rat lungs of smoke particles from combusted regular and mentholated Swisher Sweets little cigars. Twelve-week-old male and female Sprague-Dawley rats were exposed to smoke particles at a concentration of 84 ± 5 mg/m3 for 2 h, after which individual lung lobes were examined. We utilized Inductively Coupled Plasma Mass Spectrometry to quantify lobar chromium concentrations, serving as a smoke particle tracer. Our findings demonstrated an overall higher particle deposition from regular little cigars than from the mentholated ones. Higher particle deposition fraction was observed in the left and caudal lobes than other lobes. We also observed sex-based differences in the normalized deposition fractions among lobes. Animal study results were compared with the multi-path particle dosimetry (MPPD) model predictions, which showed that the model overestimated particle deposition in certain lung regions. Our findings revealed that the particle deposition varied between different little cigar products. The results demonstrated a heterogenous deposition pattern, with higher particle deposition observed in the left and caudal lobes, especially with the mentholated little cigars. Additionally, we identified disparities between our measurements and the MPPD model. This discrepancy highlights the need to enhance the accuracy of models before extrapolating animal study results to human lung deposition. Overall, our study provides valuable insights for estimating the dose of little cigars during smoking for toxicity research.

中文翻译：

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常规和薄荷醇少量雪茄烟雾在斯普拉格-道利大鼠肺部的异质沉积

量化呼吸系统中烟草烟雾的剂量和分布对于了解其毒性、成瘾潜力和健康影响至关重要。流行病学研究表明，不同肺部区域的肺部肿瘤发病率存在差异，这表明烟雾颗粒的不均匀沉积可能导致特定区域的健康风险更大。尽管如此，很少有研究检查烟草烟雾吸入颗粒的脑叶空间分布。这种知识差距，加上小雪茄在年轻人中日益流行，凸显了对小雪茄进行更多研究的必要性。在我们的研究中，我们分析了燃烧的普通和薄荷醇 Swisher Sweets 小雪茄中烟雾颗粒在大鼠肺叶中的沉积。将 12 周大的雄性和雌性 Sprague-Dawley 大鼠暴露于浓度为 84 ± 5 mg/m3 的烟雾颗粒中 2 小时，然后检查各个肺叶。我们利用电感耦合等离子体质谱法来量化叶铬浓度，作为烟雾颗粒示踪剂。我们的研究结果表明，普通小雪茄的颗粒沉积总体高于含薄荷醇的雪茄。在左叶和尾叶中观察到的颗粒沉积分数高于其他叶。我们还观察到叶间归一化沉积分数的性别差异。将动物研究结果与多路径粒子剂量测定（MPPD）模型预测进行比较，结果表明该模型高估了某些肺部区域的粒子沉积。我们的研究结果表明，不同小雪茄产品的颗粒沉积情况有所不同。结果表明，存在不均匀的沉积模式，在左叶和尾叶中观察到较高的颗粒沉积，尤其是薄荷味小雪茄。此外，我们还发现了我们的测量结果与 MPPD 模型之间的差异。这种差异凸显了在将动物研究结果外推到人类肺部沉积之前提高模型准确性的必要性。总体而言，我们的研究为估计吸烟期间小雪茄的剂量以进行毒性研究提供了宝贵的见解。