Antimicrobial Performance of an Innovative Technology of Atmospheric Plasma Reactors against Bioaerosols: Effectiveness in Removing Airborne Viable Viruses

Reducing the exposure to airborne contaminants, including bioaerosols containing viruses, is a key challenge in the context of indoor air quality. This study aims to assess the effectiveness of innovative Atmospheric Plasma Reactor (APR) technology, which can be included in air cleaner devices, as an engineering control tool for reducing the concentration of viable airborne viruses. We investigated the KillViDTM APR technology that uses ultra-high electric fields and pulsed power plasma to directly electroporate living cells and produce advanced oxidizing species in situ within the micro-droplet aerosols containing the pathogens to be treated. An experimental setup was developed in order to aerosolize a high concentration of virus suspension directly into the air cleaner, containing 3 or 6 modules of 215 atmospheric plasma micro-reactors. As a virus surrogate, we used the phi11 bacteriophage which was aerosolized using a vibrating mesh nebulizer. The viability of airborne viruses after a single pass through the air cleaner was assessed by quantifying the lysis of a specific Staphylococcus aureus host strain. We were able to demonstrate that our virucidal results were robust and showed a 5-log reduction (99.999%) in terms of virucidal activity for the 3-module configuration, while we observed at least a 6-log reduction (from an initial viral load of 9.25 × 105 PFU to 0) for the 6-module configuration