School of Energy Science and Engineering, Central South University, Changsha 410083, China; XiangYa School of Public Health, Central South University, Changsha 410078, China.
School of Energy Science and Engineering, Central South University, Changsha 410083, China.
Environ Res. 2019 Feb;169:237-245. doi: 10.1016/j.envres.2018.11.014. Epub 2018 Nov 14.
Although ambient particulate matter or particles have been found to be associated with morbidity and mortality all over the world, specific health effects of particles from different sources need further elucidation. The objective of this work is to predict the deposition of particles from different sources in the human lung. The whole lung, consisting of 24 generations of branches from trachea to alveoli, was approximated using a one-dimensional lumped "trumpet" model with a variable cross-sectional area. The aerosol dynamics equation was numerically solved using a finite difference method to investigate the transport and deposition of particles in the lung model. Particles from various sources were assumed to be different in both size and density. We found that in general, coarse particles (> 2.5 µm) were mainly deposited in the tracheobronchial (TB) region by impaction, and fine particles (< 2.5 µm) were mainly deposited in the pulmonary (P) region by sedimentation and diffusion. However, the coarse particles with low density can be deposited in P region by sedimentation. As a comparison, our results found that soil particles, which are coarse with low density, were deposited in the deep lung more than traffic particles, which are fine with high density. Modeling of particle deposition in the human lung indicated that coarse particles generated by crustal sources may have adverse health effects as strong as those resulting from fine particles generated from combustion sources.
尽管环境颗粒物或粒子已被发现与世界各地的发病率和死亡率有关，但不同来源的粒子的具体健康影响仍需进一步阐明。这项工作的目的是预测来自不同来源的粒子在人体肺部的沉积。整个肺部，由从气管到肺泡的 24 代分支组成，使用具有可变横截面积的一维集中式“喇叭”模型进行近似。使用有限差分法数值求解气溶胶动力学方程，以研究肺部模型中粒子的输运和沉积。假设来自不同来源的粒子在大小和密度上都不同。我们发现，一般来说，粗粒子（>2.5 µm）主要通过撞击沉积在气管支气管（TB）区域，而细粒子（<2.5 µm）主要通过沉降和扩散沉积在肺部（P）区域。然而，低密度的粗粒子也可以通过沉降沉积在 P 区。相比之下，我们的结果发现，密度低的土壤粒子比密度高的交通粒子更容易沉积在肺部深处。人体肺部粒子沉积模型表明，地壳源产生的粗粒子可能会产生与燃烧源产生的细粒子一样严重的不良健康影响。
