Understanding the Impact of Relative Humidity, Ozone, and Simulated Sunlight on Early Stage Aging of Infectious Bioaerosols

ELIZABETH A. KLUG, Danielle N. Rivera, Daniel N. Ackerman, Ashley R. Ravnholdt, Kevin K. Crown, Gabriel A. Lucero, Ningjin Xu, Don Collins, Joshua L. Santarpia, University of Nebraska Medical Center (UNMC)

     Abstract Number: 89
     Working Group: Bioaerosols

Abstract
Viral diseases that are transmitted as aerosols pose a significant risk to the public. This was especially evident during the COVID-19 pandemic. These viral diseases may be transmitted from person-to-person, such as SARS-CoV-2, or as environmentally generated aerosols, like hantaviruses.

The threat a virus may pose as an aerosol depends on several factors, including its stability as an aerosol. Bioaerosol stability is generally studied as the decay of aerosols properties in response to environmental conditions. Many of these studies have been accomplished using the well-known aging system, the Goldberg rotating drum. However, use of the rotating drum comes with significant drawbacks such as a failure to capture the loss of initial pathogen infectivity and a small sample volume. The Biological Aerosol Reaction Chamber (Bio-ARC) is an alternative approach that uses a flow-through system to rapidly expose large numbers of biological particles to controlled environmental conditions and determine the sensitivity and mechanisms of aging through analysis of the collected samples. Using this system, we investigated the stability of two viruses that represent two distinct types of aerosol transmission and may differ in how they respond to environmental insult: Sin Nombre Virus (SNV) and SARS-CoV-2. Both pathogens are enveloped and consist of similar protein structures. The major difference is the mode of transmission. SNV transmission occurs through the inhalation of mouse excreta in the environment and SARS-CoV-2 transmission occurs though inhalation of infectious respiratory fluids. Using the Bio-ARC, we report the first aerostability experiments with SNV, as well as the sensitivity of SARS-CoV-2 when exposed to ozone, simulated sunlight and elevated relative humidity.