Abstract
Exposure to toxic particles from smoke generated either from bush fire, stable burning, or direct smoking is very harmful to our health. The tiny particles easily penetrate deep into the lungs after exposure and damage the airways. Tobacco smoking causes the direct emission of 2.6 million tons of CO2 and 5.2 million tons of methane annually into the atmosphere. Nevertheless, it is one of the significant contributors to various respiratory diseases leading to lung cancer. These particles’ deposition in the human airway is computed in the present article for refining our understanding of the adverse health effects due to smoke particle inhalation, especially cigarette smoke. Until recently, little work has been reported to account for the transient flow pattern of cigarette smoking. Consideration of transient flow may change the deposition pattern of the particle. A high-resolution CT scan image of the respiratory tract model consisting of the oral cavity, throat, trachea, and first to sixth generations of the lungs helps predict cigarette smoke particle (CSP) deposition. With the same scan, a realistic geometric model of the human airways of an adult subject is used to simulate the transport of air and particle. The CSP deposition is determined at different locations from the oral cavity to the sixth generation of the bronchi. In addition, an unsteady breathing curve indicative of realistic smoking behavior is utilized to represent the breathing conditions accurately. The discrete phase model (DPM) technique is used to determine smoke particle deposition in the human airways. It is found that the deposition increases with the size of the smoke particle. Particles tend to deposit in the oral cavity around the bifurcation junction of the airways. The deposition fraction of CSP with the realistic waveform of smoking is found to be smaller compared to that during the stable flow condition. It is also observed that the fine particles (0.1–1.0 micron) escape to lower generations, leading to higher deposition of fine particles in the deeper airways. The outcome of the study is helpful for understanding smoke-related pulmonary complications.
Highlights
Smoke is often considered visible evidence of air pollution, which is a collection of airborne particles and gases
Around 7000 chemicals have been identified in cigarettes and other tobacco products, 250 of which are poisonous and 70 of which are carcinogenic to humans [4], causing mutagenesis of the epithelial cells leading to biologically induced cancers [5]
The results showed that the smoking style heavily influences the dose of smoke and the deposition pattern in the human respiratory tract (HRT)
Summary
Smoke is often considered visible evidence of air pollution, which is a collection of airborne particles and gases. With the progress in the flow computation, the researchers used realistic computational fluid dynamics (CFD) simulation of particle-laden airflow in the CT-scan based HRT model to predict the deposition of particles [24] and viruses [25] in the lungs utilizing arobust numerical scheme. Steffens [36], on the other hand, used the human airway from oral to third generation and computed the cigarette smoke particle deposition efficiency for various particle sizes on constant puffing and post puffing with timing 1.7 s and 3 s, respectively. Feng et al [44] computationally investigated the deposition of smoke particles emitted from electronic cigarettes in an idealized human upper airway geometry from mouth to third-generation using an Euler-Lagrangian method. NGeIcTewssaasrycaGrrIiTedwoaustcaasrrsiheodwonut in Table 1 for the present meshing scheme, and the solution is found to be grid-independent at 3,536,776 elements
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
