there are problems using UV light: sunburn and cataracts for those exposed, and the studies on Wuhan flu have not been done, and so the dosage to clean surfaces or the indoor atmosphere has to be done (some technical articles out there on this)
but I am old enough to remember whe we used it a lot in hospitals to keep germs from spreading, and then it fell out of favor. However, it’s use in hospitals is starting again, and of course, your mosquito zapper uses UV light to help kill those critters.
Ozone has also been used, if I remember correctly.
It’s got to be “UV-C”, however, and not just regular UV.
More specifically, ozone is used in water purification.
Why did they quit using it in hospitals?
It is inexpensive to install in hvac systems and effective. Same for water treatment. Been around for that application for a long time.
My take on hospitals is they are a good place to get sicker.