[colechristensen]

Much of your protection from UV radiation comes from the outer layers of dead skin cells. These people put living cells in a Petri dish under a much larger than usual dosage of these lights, serious damage should have been expected, that’s what UV does.

The question is, in vivo, do actual fingers in actual real world usage experience outsized DNA damage compared to moderate sun exposure.

You’re not going to get that answer from cultured cells like that.

If you wanted to do a study explicitly to create sensational headlines, this is how you’d do it. Take a similar situation but modify it so a bad outcome is certain then suggest the much different real world case is similar.

Given case reports of strange cancer in fingers further study is interesting, but I wouldn’t go around trying to make fans of fancy nails panic quite yet. (Who knows, some of the solvents and miscellaneous substances may be the culprit more than UV)