[TurdF3rguson]

Cumulative but with a repair mechanism. There's not necessarily "rollover exposure".

[littlexsparkee]

There are temporary as well as permanent effects and the repair mechanism can be overwhelmed: photoaging, age spots, mutations.

[TurdF3rguson]

Right but there are common precautionary rule-of-thumb heuristics which lead normal people to believe that every sun exposure brings them a little closer to death. That's exaggerated. Or at least, the claims are widely contested.

[chiply314]

Lets be honest here, every additional sun exposre means you lived longer which directly leads you closer to death sooooo ;P

[TurdF3rguson]

That part really is cumulative