hospital cleaned by UVC
Extensive research has been done exploring the effectiveness of UVC light in killing bacteria and inactivating viruses. Here are some excerpts from a few notable studies:

New Study Calls UVC Light A "Game Changer" In Fight Against Virus

In an article published by Columbia University titled "Could a New Ultraviolet Technology Fight the Spread of Coronavirus?" researcher David Brenner said he believes far-UVC light—safe for humans, but lethal for viruses—could be a ‘game changer.’

From the article:

"The research team’s experiments have shown far-UVC effective in eradicating two types of airborne seasonal coronaviruses (the ones that cause coughs and colds). The researchers are now testing the light against the SARS-CoV-2 virus at Columbia in a biosafety laboratory, with encouraging results, Brenner said.

The team previously found the method effective in inactivating the airborne H1N1 influenza virus, as well as drug-resistant bacteria. And multiple, long-term studies on animals and humans have confirmed that exposure to far-UVC does not cause damage to the skin or eyes."

Inactivation of the virus that induces severe acute respiratory syndrome, SARS-CoV published in the Journal of Virological Methods

In this study, UV-C light was used effectively against the virus that induces SARS-CoV.

Columbia University Medical Center Study Shows The Effectiveness Of UV-C light to check the spread of seasonal epidemics.

In this study, aerosolized H1N1 virus—a common strain of flu virus—was released into a test chamber and exposed to very low doses of 222 nm far-UVC light. The far-UVC light efficiently inactivated the flu virus.

“A safe and efficient method for limiting the transmission and spread of airborne-mediated microbial diseases, such as influenza and tuberculosis ... and unlike flu vaccines, far-UVC is likely to be effective against all airborne microbes, even newly emerging strains.” David J. Brenner, PhD, the Higgins Professor of Radiation Biophysics at the Vagelos College of Physicians and Surgeons and director of the Center for Radiological Research at Columbia.