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; School of Atmospheric Sciences, Sun Yat-sen University, Guangzhou 510275, PR China.
Sci Total Environ. 2019 Mar 20;657:819-826. doi: 10.1016/j.scitotenv.2018.12.067. Epub 2018 Dec 7.
Although health benefits of physical activity are well known, the risk of physical activity in polluted air is unclear. Our objective is to investigate health effects resulting from physical activity in polluted air by looking at particle deposition in human tracheobronchial (TB) airways. Airflow and particle deposition in TB airways were investigated using a computational fluid dynamics (CFD) method. We chose three regional airways: upper (G3-G5), central (G9-G11) and lower (G14-G16). Physical activity was described by breathing rate at the mouth, for three levels of activity: sedentary (15 l/min), moderate (30 l/min) and intense (60 l/min). We found that particle deposition was strongly affected by physical activity. Particles are deposited in greater number in the lower airways (G14-G16) during sedentary activity, more in the upper airways (G3-G5) during intense activity, and uniformly in the airways during moderate activity. The difference in the deposition pattern was due to the reason that physical activity increased the airflow which increased inertial impaction. Our modeling of particle deposition in the human respiratory airways shows that there are different health effects for different activity levels: sedentary activity leads to chronic health effects, intense activity results in acute effects, and moderate activity minimizes the adverse health effects of physical activity in polluted air.
尽管人们熟知身体活动对健康的好处，但在空气污染中进行身体活动的风险尚不清楚。我们的目的是通过研究人体气管支气管（TB）气道中的颗粒沉积，来调查在污染空气中进行身体活动所产生的健康影响。我们使用计算流体动力学（CFD）方法研究了 TB 气道中的气流和颗粒沉积。我们选择了三个区域气道：上气道（G3-G5）、中气道（G9-G11）和下气道（G14-G16）。通过口腔呼吸率来描述身体活动水平，分为三个活动水平：静坐（15 l/min）、中等（30 l/min）和剧烈（60 l/min）。我们发现颗粒沉积受到身体活动的强烈影响。在静坐活动时，更多的颗粒沉积在下气道（G14-G16）中；在剧烈活动时，更多的颗粒沉积在上气道（G3-G5）中；而在中等活动时，颗粒均匀地沉积在气道中。沉积模式的差异是由于身体活动增加了气流，从而增加了惯性冲击。我们对人体呼吸道中颗粒沉积的建模表明，不同的活动水平会产生不同的健康影响：静坐活动会导致慢性健康影响，剧烈活动会导致急性影响，而适度活动则可以最大限度地减少在污染空气中进行身体活动的不良健康影响。
