Nonthermal plasma air disinfection for the inactivation of airborne microorganisms in an experimental chamber and indoor air

Abstract

Aims Airborne transmission of diseases presents a serious threat to human health, so effective air disinfection technology to eliminate microorganisms in indoor air is very important. This study evaluated the effectiveness of a non-thermal plasma (NTP) air disinfector in both laboratory experiments and real environments. Methods and results An experimental chamber was artificially polluted with a bioaerosol containing bacteria or viruses. Additionally, classroom environments with and without people present were used in field tests. Airborne microbial and particle concentrations were quantified. A 3.0 log10 reduction in the initial load was achieved when a virus-containing aerosol was disinfected for 60 min and a bacteria-containing aerosol was disinfected for 90 min. In the field test, when no people were present in the room, NTP disinfection decreased the airborne microbial and particle concentrations (p < 0.05). When people were present in the room, their constant activity continuously contaminated the indoor air, but all airborne indicators decreased (p < 0.05) except for planktonic bacteria (p = 0.094). Conclusions Non-thermal plasma effectively inactivated microorganisms and particles in indoor air.