UVC Light for Airborne Epidemic Spread Prevention

The global health crisis caused by COVID-19 has highlighted the importance of preventing the spread of infection rather than focusing solely on treatment. The pandemic has not only had a profound impact on health but has also shaken social and economic systems worldwide. Effective measures to combat the epidemic should aim to limit transmission without cutting off transportation or restricting access to workplaces, as occurred during the COVID-19 outbreaks. These challenges have sparked interest in innovative strategies to contain the spread of infectious diseases through the air. Ultraviolet-C (UVC) light has proven to be a promising technology for inactivating airborne pathogens. UVC light disrupts the transcription and replication processes of microorganisms through photochemical reactions, rendering the pathogens unable to multiply or infect. However, the use of conventional UVC germicidal lamps, such as mercury vapor lamps, in public spaces is restricted due to their associated risks for human skin and eyes. Recent studies show that far-UVC light operating at shorter wavelengths (205–225 nm) can effectively inactivate a wide range of microorganisms—including viruses, bacteria, and fungi—while posing minimal risks to human health. This makes it safer to use in occupied spaces such as hospitals, schools, and public transportation. In this chapter, we review the existing literature and present results from our own experiments that demonstrate the effectiveness of far-UVC light sources, particularly at 222 nm, for aerosol sterilization. We discuss various experimental approaches, from in vitro evaluations of bactericidal efficacy to in vivo models simulating airborne virus transmission, providing a comprehensive analysis of the potential of far-UVC technology for controlling the spread of airborne epidemics.