Simple quantitative assessment of the outdoor versus indoor airborne transmission of viruses and COVID-19.

Simple quantitative assessment of the outdoor versus indoor airborne transmission of viruses and COVID-19.

B R Rowe, A Canosa, J M Drouffe, J B A Mitchell

In this paper we develop a simple model of the inhaled flow rate of aerosol particles of respiratory origin i.e. that have been exhaled by other people. A connection is made between the exposure dose and the probability of developing an airborne disease. This allows a simple assessment of the outdoor versus indoor risk of contamination to be made in a variety of meteorological situations. It is shown quantitatively that for most cases, the outdoor risk is orders of magnitude less than the indoor risk and that it can become comparable only for extremely specific meteorological and topographical situations. It sheds light on various observations of COVID-19 spreading in mountain valleys with temperature inversions while at the same time other areas are much less impacted.

2021

covid-19, Virus airborne transmission, Meteorological and topographical influence, Outdoor versus indoor transmission, Quantitative risk assessment

10.1016/j.envres.2021.111189

Environmental research