Beyond droplet deposition: Virus transport and deposition modeling in respiratory tract influenced by ambient environment and exhalation activities

Luo, Danting, Luo, Zhiwen Vincent ORCID: https://orcid.org/0000-0002-2082-3958, Zheng, Xiaohong and Qian, Hua 2024. Beyond droplet deposition: Virus transport and deposition modeling in respiratory tract influenced by ambient environment and exhalation activities. Building and Environment 255 , 111406. 10.1016/j.buildenv.2024.111406 Item availability restricted.

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Abstract

Quantifying virus deposition in the respiratory tract during exposure to various infected environments is crucial for developing effective indoor environmental interventions against airborne infectious diseases. This study presents a novel approach that combines a physical model for virus-laden droplet evaporation, size-independent viral load concentrations, and computational fluid dynamics simulations inside the respiratory tracts. We quantify the impact of exhalation activities and actual vapor pressure on virus deposition fraction (DF v ) and droplet deposition fraction (DF d ) in the respiratory tract by tracking virus-laden droplets from exhalation to inhalation to deposition. Our findings reveal that virus deposition fraction significantly differs from the droplet deposition fraction in the respiratory tract, as the minimum mean absolute percentage error (MAPE) is 0.65. Moreover, the exhalation activities and indoor conditions play a vital role in virus deposition. Considering exhalation activity is necessary for assessing the potential risk of infection in the lung lobes. The deposition fraction and copies of the virus are nearly 2-fold and over 6000-fold higher during patient speaking compared to breathing, respectively. Actual vapor pressure is also vital for the interception of the upper respiratory tract. The DF v decreases from 66.86% to 46.96% as actual vapor pressure changes from low to high. Additionally, our study quantifies the difference in virus deposition fraction between size-dependent and size-independent viral load concentrations, showing the necessity of considering size-dependent viral load concentration. Our findings improve the predictability of infection risks and can refer to the development of effective non-pharmaceutical interventions in indoor environments in the post-pandemic.

Item Type:	Article
Date Type:	Publication
Status:	Published
Schools:	Architecture
Additional Information:	License information from Publisher: LICENSE 1: Title: This article is under embargo with an end date yet to be finalised.
Publisher:	Elsevier
ISSN:	0360-1323
Date of First Compliant Deposit:	18 March 2024
Date of Acceptance:	11 March 2024
Last Modified:	08 Apr 2024 20:38
URI:	https://orca.cardiff.ac.uk/id/eprint/167308

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