Frequency Variation of Non-Thermal Plasma Effects on Inactivation of Single-Stranded DNA Virus

EMILY HONG, Zhenyu Ma, Herek L. Clack, University of Michigan

     Abstract Number: 603
     Working Group: Reducing Aerosol Exposure with Control Technologies and Interventions

Abstract
Airborne viruses are a bioaerosol of interest due to the growing concern over respiratory viruses. The COVID-19 pandemic and recent measles outbreak have brought more attention to airborne viral diseases. There is a need for the development of advanced environmental control methods which can prevent and reduce the airborne spread of viruses. The structural diversity of viruses makes it difficult to extrapolate a single virus's inactivation to other viruses. Viruses can vary based on their enveloped status, genomic material, and single or double stranded genomic material. Many previous studies have focused on the single stranded RNA virus, MS2 [1,2]. This study determines the effects of changing the frequency of our non-thermal plasma (NTP) on the performance of the plasma to inactivate single stranded DNA virus φX174. Through plaque assays, we have achieved 0.38 log (61%) inactivation of φX174 after momentary passage of the aerosols through the NTP reactor. These experiments were performed at 300 Hz and 20 kV. Previous studies have shown the largest log reductions of infectious MS2 occur at 350 Hz and 20kV when varying the frequency of the discharge from 10 to 1000 Hz [3]. However, due to the variation in virus characteristics, it is not possible to conclude 350 Hz results in the greatest log inactivation of φX174. By assessing the response of φX174 when treated at a variety of frequencies using our NTP experimental setup, it is possible to determine the greatest log reduction conditions for inactivation with this setup.

[1] Ma, Z., Dwivedi, A. K., & Clack, H. L. (2024). Effects of chemically-reductive trace gas contaminants on non-thermal plasma inactivation of an airborne virus. Science of The Total Environment, 939, 173447. https://doi.org/10.1016/j.scitotenv.2024.173447.
[2] Wu, Y., Liang, Y., Wei, K., Li, W., Yao, M., Zhang, J., & Grinshpun, S. A. (2015). MS2 Virus Inactivation by Atmospheric-Pressure Cold Plasma Using Different Gas Carriers and Power Levels. Applied and Environmental Microbiology, 81(3), 996–1002. https://doi.org/10.1128/AEM.03322-14
3. Ma, Z., Orta, S., & Clack, H. (2023). Effects of AC Frequency on Non-Thermal Plasma Inactivation of Aerosolized Viruses. 2023 IEEE Industry Applications Society Annual Meeting (IAS), 1–22. https://doi.org/10.1109/IAS54024.2023.10406920.