It is now recognized that aerosol transport contributes to the transmission of the SARS-CoV-2 virus. Here we improve existing social distancing guidelines for airborne pathogens, which are typically given in terms of distance with vague statements (if any) about contact times. Also, estimates of inhalation of virus in a contaminated space usually assume a well-mixed environment, which is realistic for some, but not all, situations. In particular, 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 social distancing guidelines that involve both space and contact time, based on a conservative model of the interactions.
Towards Improved Social Distancing Guidelines: Space and Time Dependence of Virus Transmission from Speech-driven Aerosol Transport Between Two Individuals