UVC-LED Irradiation Effectively Inactivates Aerosolized Viruses, Bacteria, and Fungi in a Chamber-Type Air Disinfection System.

UVC-LED Irradiation Effectively Inactivates Aerosolized Viruses, Bacteria, and Fungi in a Chamber-Type Air Disinfection System.

Appl Environ Microbiol. 2018 Jun 29;:

Authors: Kim DK, Kang DH

Abstract
In this study, the possibility of inactivating viral, bacterial, and fungal aerosols in a chamber-type air disinfection system by using an UVC-LED array was investigated and inactivation rate constants of each microorganism were calculated in fitting curves of surviving populations. UVC-LED array treatment effectively inactivated viral infectivity achieving 5 log reductions within 45 mJ/cm2 for MS2, Qβ, and ΦX 174 viruses. UVC-LED array effectiveness in inactivating Escherichia coli O157:H7, Salmonella enterica serovar Typhimurium, Listeria monocytogenes, and Staphylococcus aureus aerosols achieved 2.5 to 4 log reductions within 1.5 to 4.6 mJ/cm2 Also, 4 log reductions of Aspergillus flavus and Alternaria japonica were achieved at a dosage of 23 mJ/cm2 using UVC-LED array irradiation. The highest UV susceptibility, represented by the inactivation rate constant, was calculated for bacteria followed by fungi and viruses. UVC-LED, an innovative technology can effectively inactivate microorganisms regardless of taxonomic classification and can sufficiently substitute for conventional mercury UV lamps.IMPORTANCE The United Nations Environment Program (UNEP) convened the Minamata convention on mercury in 2013 to ban mercury-containing products in order to ensure human and environmental health. It will be effectuated in 2020 to discontinue use of low pressure mercury lamps and new UV emitting sources have to replace this conventional technology.However, the ultraviolet germicidal irradiation (UVGI) system still uses conventional UV lamps and no research has been conducted for air disinfection using UVC-LEDs.This research investigated the inactivation effect of aerosolized microorganisms including viruses, bacteria, and fungi with an UVC-LED module. The results can be utilized as a primary database to replace conventional UV lamps with UVC-LEDs, a novel UV emitter. Implementation of UVC-LED technology is truly expected to significantly reduce the extent of global mercury contamination and this study provides important baseline data to help ensure a healthier environment and humanity.

PMID: 29959245 [PubMed – as supplied by publisher]

Source: Industry