Inactivation of aerosolized SARS‐CoV ‐2 by 254 nm UV‐C irradiation

Abstract

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the causative agent of COVID-19, has spread since January 2020, leading to global health and social crisis. Although early on, the consensus pointed to direct contact and large droplets as the main source of infection, there is now growing evidence that the virus is transmitted by aerosols, 1 which might be even the main route of transmission. 2 Aerosols, as the major transmission route, better explains the superspreading events and the large proportion of infections generated from asymptomatic people. 3 Small aerosol particles can be suspended and travel through the air. In the case of SARS-CoV-2, it was shown that they can remain viable for 3 h and float for several hours. 4 In this context, there is an urgent need for technologies that allow decontamination of breathing air, for instance, in public transportation, schools, hospitals, and many other settings. Currently, mechanical (mainly HEPA14 and 13) filters are used for such purposes with certain limitations related to the size, energy demand, noise, capacity, and need for ongoing maintenance. Other inactivating technologies, based for instance on cold plasma and ultraviolet germicidal irradiation using UV-C are discussed and partly already in use.UV-C disinfection has been used for several decades to inactivate different infectious agents, including fungi, bacteria, and viruses, both from contaminated liquids and surfaces. [5][6][7] Although the primary mode of action for UV inactivation is considered to be genome damaging through the formation of pyrimidine dimers 8-10 different mechanisms have been described. These include protein oxidation, destruction of the capsid protein, and crosslinking of viral genome-protein. 11 Regarding decontamination of coronaviruses, it was previously shown that non-human coronaviruses as well as common-cold coronaviruses and SARS-CoV are sensitive to

Inactivation characteristics of a 280 nm Deep-UV irradiation dose on aerosolized SARS-CoV-2

“…Compared with the experimental results of the inactivation of aerosolized SARS-CoV-2 conducted by Ruetalo et al (2022) and Ueki et al (2022) ( Table 1 ), the total irradiation dose required for a virus inactivation rate of nearly 99.9% in this study was slightly higher. This result was expected as the emission wavelengths of the LEDs used in the previous studies were 254 nm ( Ruetalo et al, 2022 ) and 265 nm ( Ueki et al, 2022 ), shorter than those used in this study.…”

“…Compared with the experimental results of the inactivation of aerosolized SARS-CoV-2 conducted by Ruetalo et al (2022) and Ueki et al (2022) ( Table 1 ), the total irradiation dose required for a virus inactivation rate of nearly 99.9% in this study was slightly higher. This result was expected as the emission wavelengths of the LEDs used in the previous studies were 254 nm ( Ruetalo et al, 2022 ) and 265 nm ( Ueki et al, 2022 ), shorter than those used in this study. Previous studies in which SARS-CoV-2 solution was dropped onto a Petri dish or well plate also showed that DUV light with a wavelength of 254 nm ( Sabino et al, 2020 ) or 265 nm ( Ueki et al, 2022 ) could inactivate the virus by up to 99.9% at less irradiation dose compared to that with a wavelength of 280 nm ( Inagaki et al, 2020 ).…”

“…The effects of DUV-LEDs on aerosolized SARS-CoV-2 have rarely been reported ( Ruetalo et al, 2022 , Ueki et al, 2022 , Takamure et al, 2022 ). Among the few reports, Ruetalo et al, 2022 , Ueki et al, 2022 irradiated aerosolized SARS-CoV-2 with 254-nm and 265-nm DUV-LEDs and achieved a virus inactivation rate of 99.9% at 0.42–0.51 mJ/cm 2 and 1.04 mJ/cm 2 , respectively.…”

“…The effects of DUV-LEDs on aerosolized SARS-CoV-2 have rarely been reported ( Ruetalo et al, 2022 , Ueki et al, 2022 , Takamure et al, 2022 ). Among the few reports, Ruetalo et al, 2022 , Ueki et al, 2022 irradiated aerosolized SARS-CoV-2 with 254-nm and 265-nm DUV-LEDs and achieved a virus inactivation rate of 99.9% at 0.42–0.51 mJ/cm 2 and 1.04 mJ/cm 2 , respectively. This finding indicates that approximately 1/10 of the total irradiation dose can inactivate the virus to the limit of detection, compared to adding the virus solution to the Petri dish.…”

NUMERICAL SIMULATION OF THE INFLUENCE OF SOME GEOMETRIC PARAMETERS ON THE DECONTAMINATION QUALITY OF A NON-LAMBERTIAN TYPE DETECTOR, USING A UV-C LEDs MATRIX

“…UV-C is already used successfully in various fields, such as medicine, ecology, postharvest technologies etc., alone (Rodgers et al, 2023;Calle et al, 2023;Meneses-Espinosa et al, 2023;Ruetalo et al, 2022;Yemmireddy et al, 2022;Iturralde-García et al 2022;Cruz Mendoza et al, 2022;Berruti et al, 2021;Sorică et al, 2021), or in combination with other methods (e.g. the use of ozone) (Sottani et al, 2023;Dogu-Baykut et al, 2022;Martínez de Alba et al, 2021;Frigerio et al, 2021;Gutiérrez et al, 2017).…”