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The UV index is not the warm sensation of sunlight on bare skin

99 points · 79 comments · evakhoury

  1. Terr_ · · focus · HN ↗
    > Sunburn is triggered when your DNA is damaged from light absorption [...] This interferes with protein synthesis and wreaks havoc in your body over time

    Not a skin-scientist, but this seems misleading: Sunburn is not caused by some bad DNA floating around, nor damaged cells making making mistakes or pumping out wrong proteins to inflame their neighbors.

    Instead, your cells have techniques to measure a variety of risk factors and signals (which does include DNA-molecule weirdness [0]) and when things get too risky the well-behaved ones will self-destruct, to avoid the chance of turning into a cancer.

    So the sunburn you see and feel is instead due to cells signalling "something damaged me and I can't be trusted, I'm shutting down, recycle me" to your immune-system, plus the attendant bustle of hazmat-cleanup and increased security-sweeps for cancer-leftovers and other potential causes of the damage.

    [0] <a href="https:&#x2F;&#x2F;www.nature.com&#x2F;articles&#x2F;newbio241074a0" rel="nofollow">https:&#x2F;&#x2F;www.nature.com&#x2F;articles&#x2F;newbio241074a0

    1. rogerrogerr · · focus · HN ↗
      Our immune system is _so cool_. Seems like every week I learn something new about it.
      1. [deleted] · · focus · HN ↗

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