Dyes have electron delocalization. That's why they're optically active. Those bonds will gladly participate in chemical reactions within your body. (One of the cited chemicals was a biphenyl, and looked particularly nasty.)
Chemical straightener is even worse. They're intended to break disulfide bonds, which are of critical importance in biochemical structure.
This stuff could percolate to your DNA and introduce deleterious changes.
You might find my work based on the HN front page of interest: <https://toot.cat/@dredmorbius/110437783957361794>. Note that this is a subset of total HN activity, though a significant subset.
There's also Whaly.io's retrospectives based on the HN API:
<https://whaly.io/posts/hacker-news-2021-retrospective>
<https://whaly.io/posts/top-10k-commenters-of-hacker-news-in-...>
Really interesting analysis. Thanks for sharing this!
I must be too active on HN when my username is showing up in these lists.
I've been having fun going through the data, and yes, there are some interesting bits that turn up. Quite a few unexpected. Validating the "flamewar detector" wasn't on my bingo card, but I've largely done that.
I'm also ... far too well represented in the data....