Towards Improved Social Distancing Guidelines: Space and Time Dependence of Virus Transmission from Speech-driven Aerosol Transport Between Two Individuals

It is now recognized that aerosol transport contributes to the transmission of the SARS-CoV-2. Existing social distancing guidelines are given in terms of distance, with vague statements about contact times. Also, estimates of inhalation of virus in a contaminated space typically assume a well-mixed environment, which is realistic for some, but not all, situations. We consider a local casual interaction of an infected individual and a susceptible individual, both maskless, account for the air flow and aerosol transport characteristics of speaking and breathing, and propose guidelines that involve both space and contact time, based on a conservative model of the interactions.