Qihong Deng1, Cuiyun Ou2, Jiao Chen2, Yuguang Xiang2. 1. School of Energy Science and Engineering, Central South University, Changsha, China; XiangYa School of Public Health, Central South University, Changsha, China. Electronic address: qhdeng@csu.edu.cn. 2. School of Energy Science and Engineering, Central South University, Changsha, China.
Abstract
BACKGROUND: Particle deposition in human airways is important for assessing both health effects of inhaled particles and therapeutic efficacy of inhaled drug aerosols, but is not well understood for infants and children. OBJECTIVE: We investigate particle deposition in infants and children by using computational fluid dynamics (CFD), and compare this with particle deposition in adults. METHODS: We chose three population age groups: 7-month infant, 4-year old child, and 20-year old adult. Both airway structures and breathing conditions are considered to vary as a human grows from infancy to adulthood. We investigated deposition of micron-size particles (1-10μm) in both the upper (G3-G6) and lower (G9-G12) tracheobronchial (TB) airways under sedentary conditions. RESULTS: We found that particle deposition in both upper and lower airways is the highest in an infant, next in a child, and lowest in an adult. As age increases, particle deposition decreases in the upper airways but increases in the lower. For infants, inertial impaction is the dominant deposition mechanism, thus particles are deposited more in the upper airways than in the lower. However, particles are deposited more in the lower airways than in the upper in adults, as gravitational sedimentation is the dominant deposition mechanism. CONCLUSION: Given the differences in the airway structure and particle deposition mechanisms, particle deposition in infants and children differs from that in adults, not only in the efficiency of deposition but also in the site. Our findings provide evidence that "children are not small adults".
BACKGROUND: Particle deposition in human airways is important for assessing both health effects of inhaled particles and therapeutic efficacy of inhaled drug aerosols, but is not well understood for infants and children. OBJECTIVE: We investigate particle deposition in infants and children by using computational fluid dynamics (CFD), and compare this with particle deposition in adults. METHODS: We chose three population age groups: 7-month infant, 4-year old child, and 20-year old adult. Both airway structures and breathing conditions are considered to vary as a human grows from infancy to adulthood. We investigated deposition of micron-size particles (1-10μm) in both the upper (G3-G6) and lower (G9-G12) tracheobronchial (TB) airways under sedentary conditions. RESULTS: We found that particle deposition in both upper and lower airways is the highest in an infant, next in a child, and lowest in an adult. As age increases, particle deposition decreases in the upper airways but increases in the lower. For infants, inertial impaction is the dominant deposition mechanism, thus particles are deposited more in the upper airways than in the lower. However, particles are deposited more in the lower airways than in the upper in adults, as gravitational sedimentation is the dominant deposition mechanism. CONCLUSION: Given the differences in the airway structure and particle deposition mechanisms, particle deposition in infants and children differs from that in adults, not only in the efficiency of deposition but also in the site. Our findings provide evidence that "children are not small adults".
Authors: Carlos F Ugas-Charcape; María Elena Ucar; Judith Almanza-Aranda; Emiliana Rizo-Patrón; Claudia Lazarte-Rantes; Pablo Caro-Domínguez; Lina Cadavid; Lizbet Pérez-Marrero; Tatiana Fazecas; Lucía Gomez; Mariana Sánchez Curiel; Walter Pacheco; Ana Rizzi; Andrés García-Bayce; Efigenia Bendeck; Mario Montaño; Pedro Daltro; José D Arce-V Journal: Pediatr Radiol Date: 2021-04-01
Authors: Mohammad S Islam; Puchanee Larpruenrudee; Sheikh I Hossain; Mohammad Rahimi-Gorji; Yuantong Gu; Suvash C Saha; Gunther Paul Journal: Int J Environ Res Public Health Date: 2021-06-09 Impact factor: 3.390