The effects of indoor temperature and humidity on local transmission of COVID-19 and how it relates to global trends

Han June Park; Sung-Gwang Lee; Jeong Suk Oh; Minhyuk Nam; Steven Barrett; Soohyung Lee; Wontae Hwang

doi:10.1371/journal.pone.0271760

The effects of indoor temperature and humidity on local transmission of COVID-19 and how it relates to global trends

PLoS One. 2022 Aug 10;17(8):e0271760. doi: 10.1371/journal.pone.0271760. eCollection 2022.

Authors

Han June Park¹, Sung-Gwang Lee¹, Jeong Suk Oh², Minhyuk Nam³, Steven Barrett², Soohyung Lee⁴, Wontae Hwang^{1

5}

Affiliations

¹ Department of Mechanical Engineering, Seoul National University, Seoul, South Korea.
² Department of Aeronautics and Astronautics, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America.
³ Department of Economics, Sogang University, Seoul, South Korea.
⁴ Graduate School of International Studies, Seoul National University, Seoul, South Korea.
⁵ Institute of Advanced Machines and Design, Seoul National University, Seoul, South Korea.

Abstract

During the COVID-19 pandemic, analyses on global data have not reached unanimous consensus on whether warmer and humid weather curbs the spread of the SARS-CoV-2 virus. We conjectured that this lack of consensus is due to the discrepancy between global environmental data such as temperature and humidity being collected outdoors, while most infections have been reported to occur indoors, where conditions can be different. Thus, we have methodologically investigated the effect of temperature and relative humidity on the spread of expired respiratory droplets from the mouth, which are assumed to be the main cause of most short-range infections. Calculating the trajectory of individual droplets using an experimentally validated evaporation model, the final height and distance of the evaporated droplets is obtained, and then correlated with global COVID-19 spread. Increase in indoor humidity is associated with reduction in COVID-19 spread, while temperature has no statistically significant effect.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

COVID-19* / epidemiology
Humans
Humidity
Pandemics
SARS-CoV-2
Temperature

Grants and funding

This work was supported by Seoul National University Research Grant in 2020 and supported under the framework of international cooperation program managed by the National Research Foundation of Korea (2020K2A9A1A01096358, FY2020). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.