American Association for Aerosol Research - Abstract Submission

AAAR 39th Annual Conference
October 18 - October 22, 2021

Virtual Conference

Abstract View


Droplets and Aerosols in Infectious Disease Transmission: History of the 5-μm Cutoff and the 6' Rule

Katherine Randall, E. Thomas Ewing, LINSEY MARR, Jose-Luis Jimenez, Lydia Bourouiba, Virginia Tech

     Abstract Number: 593
     Working Group: Translating Aerosol Research for Societal Impact: Science Communication and Public Outreach

Abstract
The COVID-19 pandemic has exposed major gaps in our understanding of the transmission of viruses through the air. These gaps slowed recognition of airborne transmission of the disease, contributed to muddled public health policies, and impeded clear messaging on how best to slow transmission of COVID-19. In particular, current recommendations have been based on four tenets: 1) respiratory disease transmission routes can be viewed mostly in a binary manner of “droplets” versus “aerosols”; 2) this dichotomy depends on droplet size alone; 3) the cutoff size between these routes of transmission is 5 μm; and 4) there is a dichotomy in the distance at which transmission by each route is relevant. Yet, a relationship between these assertions is not supported by current scientific knowledge. Here, we revisit the historical foundation of these notions, and how they became entangled from the 1800s to today, with a complex interplay among various fields of science and medicine. This journey into the past highlights potential solutions for better collaboration and integration of scientific results into practice for building a more resilient society with more sound, far-sighted, and effective public health policies.