Germicidal UV could make airborne diseases as rare as those carried by water

Idiotic and massively overlooks/underestimates how complex biology is.

What about beneficial and neutral but important bacteria and viruses? "Air" is actually a complex soup of all types of things. This like applying HCl to a skin infection.

Studying a building's microbiome is really a new field. What happens to people if offices become boxes of sterile air and -surfaces? We don't know.

I would consider it unlikely that airborne germs form a significant input to our microbiomes.

For example, the gut microbiome is in flux for about the first 3 years of life, and thereafter it's mostly only the relative abundances of different microbes that shift in response to diet, you need something like antibiotics or severe diarrhea to actually induce permanent changes (usually for the worse).

Compared to that, there really aren't many microbes in the air. For children, it could very possibly be bad, but even then I'd expect most of their microbial input to come from their parents, food, and surfaces. Which are already grossly deficient compared to old-school rural settings, but I'm not sure if germicidal UV would make it worse.

> What about beneficial and neutral but important bacteria and viruses?

Such as what? There are some located in the gut, but pretty much everything else out there is in conflict with our immune system.

I doubt it would be a problem for the microbiome [1] but I would worry about the immune system. Would being inside in sterilized air all the time mean you can't go outside or into a forest without getting really sick?

[1] but who am I, it would still be worthwhile to check obviously

where are you getting this info?

almost every mucosal surface has commensal bacteria which can provide colonization resistance by other bacteria. lungs, skin, vagina, etc..

The underlying thought is that outside air (such as a forest) gets UV sterilized by the sun. So this would bring inside air up to the sterilization level of outside air.

I recently read the book "Invisible Friends," and in it, among other things, the author does go on to explain that it's theorised that many skin infections come from a lack of biodiversity in a persons' skin microbiome, because the "good" or neutral microbes compete with the "bad" for resources. Supposedly people who share a house together often have similar gut microbiomes, too.

So yeah, I don't know. I think you have a point here.

That's not how the immune system works. Practice lets it learn how to fight specific bugs, it doesn't make it stronger overall.

Ah, that makes sense.

I did not mean to imply at all that the immune system works like that.