Modeling the infection risk and emergency evacuation from bioaerosol leakage around an urban vaccine factory

• Published in: NPJ climate and atmospheric science Vol. 6; no. 1; p. 6
• Main Authors: Liu, Zhijian, Cao, Hongwei, Hu, Chenxing, Wu, Minnan, Zhang, Siqi, He, Junzhou, Jiang, Chuan
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 01.01.2023; Nature Publishing Group UK; Nature Portfolio
• Subjects: Airborne microorganisms; Algorithms; Bioaerosols; COVID-19; Deposition; Emergency preparedness; Emergency response; Evacuation; Evacuation routing; Greedy algorithms; Health risks; High rise buildings; Infections; Leakage; Modelling; Risk assessment; Thermal stratification; Urban environments; Vaccines; Environmental impact; Atmospheric dynamics
• ISSN: 2397-3722; 2397-3722
• DOI: 10.1038/s41612-023-00342-1

Mounting interest in modeling outdoor diffusion and transmission of bioaerosols due to the prevalence of COVID-19 in the urban environment has led to better knowledge of the issues concerning exposure risk and evacuation planning. In this study, the dispersion and deposition dynamics of bioaerosols around a vaccine factory were numerically investigated under various thermal conditions and leakage rates. To assess infection risk at the pedestrian level, the improved Wells-Riley equation was used. To predict the evacuation path, Dijkstra's algorithm, a derived greedy algorithm based on the improved Wells-Riley equation, was applied. The results show that, driven by buoyancy force, the deposition of bioaerosols can reach 80 m on the windward sidewall of high-rise buildings. Compared with stable thermal stratification, the infection risk of unstable thermal stratification in the upstream portion of the study area can increase by 5.53% and 9.92% under a low and high leakage rate, respectively. A greater leakage rate leads to higher infection risk but a similar distribution of high-risk regions. The present work provides a promising approach for infection risk assessment and evacuation planning for the emergency response to urban bioaerosol leakage.