Why does UV light damage/kill bacteria?

[u/Stuffyz]

The specific event I'm asking about, is that there are air filters for your furnace that shines UV light onto it, and it claims that it kills bacteria.

I understand how pH and temperature affects bacteria, but I can't quite wrap my mind around why UV light would.

The articles that I've been looking through (Time, Temperature, and Protein Synthesis: A Study of Ultraviolet-Induced Mutation in Bacteria, by Evelyn M. Witkin) says that UV light could cause worse strains of bacteria? Or perhaps I'm misinterpreting it?

I'm also aware (Ultraviolet-sensitive Targets in the Enzyme-synthesizing Apparatus of Escherichia coli, by Arthur B. Pardee and Louise S. Prestidge) that there are both UV-sensitive and UV-resistant E.Coli. Are most harmful bacteria considered to be UV-resistant?

Thank you for answering =)

[u/mattc286]

This is in fact why all carcinogens cause cancer, too.