UV Light to Limit COVID-19 Transmission

An international team of researchers advocates the use of UV-C light in indoor spaces as a way to reduce the transmission of SARS-CoV-2 viruses

This solution meets the requirements of fast, scalable, and affordable implementation to fulfill the needs of disinfecting workspaces, such as offices, schools, healthcare facilities, and public transportation, to name a few 

Pathways of viral infection in everyday life shown in a simplified scheme (top) and illustrated by pictorial descriptions of exposure to the virus in everyday activities (bottom). Placement of UV-C light sources at ventilation systems and rooms not in use, without direct optical paths to humans, help reduce virus propagation. Image sketches by Nacho Gaubert

The COVID-19 outbreak, caused by the SARS-CoV-2 virus, is posing an extraordinary challenge that requires swift worldwide action for the massive deployment of affordable and ready-to-apply measures to drastically reduce its transmission probabilities in indoor spaces. Doing so will allow for the eventual return to conventional activities such as working at the office, going to school, or even attending entertainment events. 

Studies show that virus transmission follows two main paths. Firstly, the virus can be transmitted through the air in droplets exhaled by infected individuals and inhaled by healthy individuals. Secondly, it can be deposited on surfaces from exhalations or hand contact. Several measures are being adopted to help prevent the transmission of this disease. The most common ones refer to facial masks and other physical barriers that if properly used, have proven to be highly effective. However, such measures depend on the compliance of the population. 

Prof. Ido Kaminer

A long series of studies suggest that virus transmission in indoor spaces is much higher than outdoors. Filters and chemicals have been presented as possible solutions to minimize this problem, but despite their effectiveness in reducing the concentration of contaminated particles and droplets passing through ventilation systems, their installation may be costly and time-consuming. In addition, some chemicals that are very effective for virus disinfection, such as ozone, can be harmful if misused.

To address this dilemma, an international team of experts in the fields of virology, immunology, aerosols, architecture, and physics studied various methods to prevent SARS-CoV-2 propagation in indoor spaces. Based on their findings, published recently in ACS Nano, they are advocating for one measure that they believe to be “particularly efficient, easily deployable, and economically affordable”: virus inactivation by ultraviolet light. 

The research was conducted by Technion Professor Ido Kaminer, in collaboration with ICREA Prof. Javier García de Abajo at ICFO, ICREA Profs. Andreas Meyerhans (Universitat Pompeu Fabra) and Joan Rosell-Llompart (University Rovira i Virgili), together with Profs. Rufino Javier Hernández (University of the Basque Country), and Tilman Sanchez-Elsner (University of Southampton). 

After researching currently available UV-C sources, such as fluorescent lamps, microcavity plasmas, and LEDs, the team concluded that applying this type of light on the inside of the ventilation systems of buildings and in shared indoor spaces while not in use, makes it possible to quickly and efficiently deactivate both airborne and surface-deposited SARS-CoV-2 viruses.

The team also explored the cost of deploying such technology and argue that a global capital investment of a few billion dollars in UV-C sources could protect more than a billion indoor workers worldwide.

Click here for the paper in ACS Nano