A psychrometric model to assess the biological decay of the SARS-CoV-2 virus in aerosols

Clive B Beggs; Eldad J Avital

doi:10.7717/peerj.11024

A psychrometric model to assess the biological decay of the SARS-CoV-2 virus in aerosols

PeerJ. 2021 Mar 2:9:e11024. doi: 10.7717/peerj.11024. eCollection 2021.

Authors

Clive B Beggs^#¹, Eldad J Avital^#²

Affiliations

¹ Carnegie School of Sport, Leeds Beckett University, Leeds, UK.
² School of Engineering and Materials Science, Queen Mary University of London, London, UK.

^# Contributed equally.

Abstract

There is increasing evidence that the 2020 COVID-19 pandemic has been influenced by variations in air temperature and humidity. However, the impact that these environmental parameters have on survival of the SARS-CoV-2 virus has not been fully characterised. Therefore, an analytical study was undertaken using published data to develop a psychrometric model to assess the biological decay rate of the virus in aerosols. This revealed that it is possible to describe with reasonable accuracy (R ² = 0.718, p < 0.001) the biological decay constant for the SARS-CoV-2 virus using a regression model with enthalpy, vapour pressure and specific volume as predictors. Applying this to historical meteorological data from London, Paris and Milan over the pandemic period, produced results which indicate that the average half-life of the virus in aerosols outdoors was in the region 13-22 times longer in March 2020, when the outbreak was accelerating, than it was in August 2020 when epidemic in Europe was at its nadir. However, indoors, this variation is likely to be much less. As such, this suggests that changes in virus survivability due the variations in the psychrometric qualities of the air might influence the transmission of SARS-CoV-2.

Keywords: Aerosols; Biological decay; Psychrometric model; SARS-CoV-2.

Grants and funding

This work was supported by the UK Royal Academy of Engineering under the programme Engineering X Pandemic Preparedness, grant EXP2021/1/247. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.