Far-UVC light (200–230 nm) can inactivate pathogens while being human-safe as it can't penetrate the outer nonliving layers of skin and cornea. Lab studies on aerosolised virus have demonstrated promising results, but so far, no epidemiological study in a real-world setting has been published. Afaik, one such study is currently being performed in Canadian retirement homes, and multiple groups are currently designing epidemiological studies as well.

For reference, upper-room UVC air disinfection (using 254 nm lamps illuminating and disinfection only the upper part of the room) was common in the 1950s/60s for tuberculosis control and reduced tuberculosis incidences by an average of ~40 %.

What percent in total disease reduction will the first real-world epidemiological study on the effects of far-UVC air disinfection show?

I don't expect a negative effect, but the range extends to –10 % (i.e. 10 % more disease in the far-UVC group) to allow distributions around 0 % (no measured effect size).

Apr 2, 12:57pm: What will the outcome of an epidemiological study of far-UVC air disinfection be? → What % disease reduction will an epidemiological study of far-UVC air disinfection show?