I was curious about the UV applications out there a few weeks ago, and there is much. I read that the lower UV range, say 220 - 250 will mess up the pathogens, but not have the adverse effect on human skin. There are some systems that can run for a few hours overnight to kill pathogens in the air when people aren't present, and I think I saw something about them being installed in ventilations systems as well. Dr. Birx was on the board or a consultant to one company I noticed...
Steve