Institute of Public Safety Research, Department of Engineering Physics, Tsinghua University, Beijing, China.
Beijing Key Laboratory of City Integrated Emergency Response Science, Department of Engineering Physics, Tsinghua University, Beijing, China.
Inhal Toxicol. 2020 Nov-Dec;32(13-14):456-467. doi: 10.1080/08958378.2020.1840679. Epub 2020 Oct 30.
The exposure to airborne particles are of great concern in public health. The present study was aimed to clarify the effects of the breathing mode (nasal and oral inhalation) and exposure conditions on particle inhalation and deposition in human airway.
A scanned upper airway embedded body model in an extended computational domain was constructed to perform numerical investigation into the inhalation and deposition of airborne particles.
It was clarified that the inhalation of sub-micro and micro particles was of high efficiency and insensitive to the breathing mode, while super microparticles were much less inhalable, in particular under the nasal intake. Moreover, the relative variation of environmental wind speed and direction could significantly reshape the breathing zone as well as modify the critical inhalable area at far upstream. In addition, the breathing mode was found to be affective on the regional deposition of the microparticles, and increasing the proportion of nasal inhalation flowrate slightly enhanced the total deposition in the upper airway model.
The breathing mode and exposure conditions significantly influence the particle inhalability and deposition pattern in human airway, which should be considered in the evaluation of health risk associated with airborne particle exposure.
空气中颗粒的暴露对公共健康有很大影响。本研究旨在阐明呼吸模式（鼻腔和口腔吸入）和暴露条件对人体气道中颗粒吸入和沉积的影响。
构建了一个扩展计算域内嵌入的扫描上呼吸道体模型，对空气中颗粒的吸入和沉积进行数值研究。
结果表明，亚微米和微米颗粒的吸入效率很高，对呼吸模式不敏感，而超微颗粒的吸入性要差得多，特别是在鼻腔吸入的情况下。此外，环境风速和风向的相对变化可以显著改变呼吸区，并在下游上游改变临界可吸入区域。此外，呼吸模式对微粒的区域沉积有影响，增加鼻腔吸入流量的比例会略微增加上呼吸道模型中的总沉积量。
呼吸模式和暴露条件显著影响人体气道中颗粒的可吸入性和沉积模式，在评估与空气中颗粒暴露相关的健康风险时应予以考虑。
