Dispersion of evaporating cough droplets in tropical outdoor environment

The ongoing Covid-19 pandemic has focused our attention on airborne droplet transmission. In this study, we simulate the dispersion of cough droplets in a tropical outdoor environment, accounting for the effects of non-volatile components on droplet evaporation. The effects of relative humidity, win...

Descripción completa

Detalles Bibliográficos
Autores principales: Li, Hongying, Leong, Fong Yew, Xu, George, Ge, Zhengwei, Kang, Chang Wei, Lim, Keng Hui
Formato: Online Artículo Texto
Lenguaje:English
Publicado: AIP Publishing LLC 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7685245/
https://www.ncbi.nlm.nih.gov/pubmed/33244215
http://dx.doi.org/10.1063/5.0026360
_version_ 1783613149034840064
author Li, Hongying
Leong, Fong Yew
Xu, George
Ge, Zhengwei
Kang, Chang Wei
Lim, Keng Hui
author_facet Li, Hongying
Leong, Fong Yew
Xu, George
Ge, Zhengwei
Kang, Chang Wei
Lim, Keng Hui
author_sort Li, Hongying
collection PubMed
description The ongoing Covid-19 pandemic has focused our attention on airborne droplet transmission. In this study, we simulate the dispersion of cough droplets in a tropical outdoor environment, accounting for the effects of non-volatile components on droplet evaporation. The effects of relative humidity, wind speed, and social distancing on evaporative droplet transport are investigated. Transmission risks are evaluated based on SARS-CoV-2 viral deposition on a person standing 1 m or 2 m away from the cougher. Our results show that the travel distance for a 100 µm droplet can be up to 6.6 m under a wind speed of 2 m/s. This can be further increased under dry conditions. We found that the travel distance of a small droplet is relatively insensitive to relative humidity. For a millimetric droplet, the projected distance can be more than 1 m, even in still air. Significantly greater droplets and viral deposition are found on a body 1 m away from a cougher, compared to 2 m. Despite low inhalation exposure based on a single cough, infection risks may still manifest through successive coughs or higher viral loadings.
format Online
Article
Text
id pubmed-7685245
institution National Center for Biotechnology Information
language English
publishDate 2020
publisher AIP Publishing LLC
record_format MEDLINE/PubMed
spelling pubmed-76852452020-11-24 Dispersion of evaporating cough droplets in tropical outdoor environment Li, Hongying Leong, Fong Yew Xu, George Ge, Zhengwei Kang, Chang Wei Lim, Keng Hui Phys Fluids (1994) ARTICLES The ongoing Covid-19 pandemic has focused our attention on airborne droplet transmission. In this study, we simulate the dispersion of cough droplets in a tropical outdoor environment, accounting for the effects of non-volatile components on droplet evaporation. The effects of relative humidity, wind speed, and social distancing on evaporative droplet transport are investigated. Transmission risks are evaluated based on SARS-CoV-2 viral deposition on a person standing 1 m or 2 m away from the cougher. Our results show that the travel distance for a 100 µm droplet can be up to 6.6 m under a wind speed of 2 m/s. This can be further increased under dry conditions. We found that the travel distance of a small droplet is relatively insensitive to relative humidity. For a millimetric droplet, the projected distance can be more than 1 m, even in still air. Significantly greater droplets and viral deposition are found on a body 1 m away from a cougher, compared to 2 m. Despite low inhalation exposure based on a single cough, infection risks may still manifest through successive coughs or higher viral loadings. AIP Publishing LLC 2020-11-01 /pmc/articles/PMC7685245/ /pubmed/33244215 http://dx.doi.org/10.1063/5.0026360 Text en © 2020 Author(s) Published under license by AIP Publishing. 1070-6631/2020/32(11)/113301/11/$30.00 All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle ARTICLES
Li, Hongying
Leong, Fong Yew
Xu, George
Ge, Zhengwei
Kang, Chang Wei
Lim, Keng Hui
Dispersion of evaporating cough droplets in tropical outdoor environment
title Dispersion of evaporating cough droplets in tropical outdoor environment
title_full Dispersion of evaporating cough droplets in tropical outdoor environment
title_fullStr Dispersion of evaporating cough droplets in tropical outdoor environment
title_full_unstemmed Dispersion of evaporating cough droplets in tropical outdoor environment
title_short Dispersion of evaporating cough droplets in tropical outdoor environment
title_sort dispersion of evaporating cough droplets in tropical outdoor environment
topic ARTICLES
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7685245/
https://www.ncbi.nlm.nih.gov/pubmed/33244215
http://dx.doi.org/10.1063/5.0026360
work_keys_str_mv AT lihongying dispersionofevaporatingcoughdropletsintropicaloutdoorenvironment
AT leongfongyew dispersionofevaporatingcoughdropletsintropicaloutdoorenvironment
AT xugeorge dispersionofevaporatingcoughdropletsintropicaloutdoorenvironment
AT gezhengwei dispersionofevaporatingcoughdropletsintropicaloutdoorenvironment
AT kangchangwei dispersionofevaporatingcoughdropletsintropicaloutdoorenvironment
AT limkenghui dispersionofevaporatingcoughdropletsintropicaloutdoorenvironment