Effects of non-thermal plasma on disinfection of indoor air and reduction of particulate matter

concentration in the chamber, after adjustment for natural decay. Under unoccupied conditions, airborne bacterial concentrations were significantly decreased after 90 min of NTP disinfection, when compared with no treatment. Under occupied conditions, although human activities increased bacterial and PM levels, both indicators declined with prolonged disinfection duration. The highest bacterial load occurred in the 1.1-2.1-µm particle-size fraction. Thus, controlling the number of occupants and minimizing unnecessary door opening during clinical procedures may enhance disinfection efficiency. Overall, NTP effectively inactivated airborne bacteria and removed PM, showing promising potential for improving indoor air quality and reducing airborne disease transmission risks.