ABSTRACT
Far UV-C, informally defined as electromagnetic radiation with wavelengths between 200 and 230 nm, has characteristics that are well-suited to control of airborne pathogens. Specifically, Far UV-C has been shown to be highly effective for inactivation of airborne pathogens;yet this same radiation has minimal potential to cause damage to human skin and eye tissues. Critically, unlike UV-B, Far UV-C radiation does not substantially penetrate the dead cell layer of skin (stratum corneum) and does not reach germinative cells in the basal layer. Similarly, Far UV-C radiation does not substantially penetrate through corneal epithelium of the eye, thereby preventing exposure of germinative cells within the eye. The most common source of Far UV-C radiation is the krypton chloride excimer (KrCl*) lamp, which has a primary emission centered at 222 nm. Ozone production from KrCl* lamps is modest, such that control of indoor ozone from these systems can be accomplished easily using conventional ventilation systems. This set of characteristics offers the potential for Far UV-C devices to be used in occupied spaces, thereby allowing for improved effectiveness for inactivation of airborne pathogens, including those that are responsible for COVID-19. © 2022 The Author(s). Published with license by Taylor & Francis Group, LLC.
ABSTRACT
The interaction of electromagnetic (EM) waves with the COVID-19 virus is studied to define the frequencies that cause maximum energy absorption by the virus and the power level needed to cause a lethal temperature rise. The full-wave EM simulator is used to model the virus and study the effects of its size and dielectric properties on the absorbed power across a wide range of frequencies. The results confirm potential resonance conditions, where specific frequencies produce maximum absorption and subsequent temperature rise that can destroy the virus. Furthermore, the study confirms that maximum power deposition in the virus occurs at specific wavelengths depending on its size. Also, the simulation is used to find the power required to destroy the virus and determine the total power required to destroy it in an oral activity, such as coughing, made by infected individuals. Furthermore, the study explained why irradiation by UV-C band is effective to decrease virus activity or even eradicate it.