The person you responded to didn't say anything about harm to themselves. They said there's nothing stopping them from donating even though they're aware of the PFAS contamination in their area.
And from what I understand, PFA contamination has no bearing on whether or not you can donate.
The post implied that doing a “blood oil change” was potentially a good thing. My point is, we don’t know either way, because a study hasn’t looked at that question for health outcomes. It could be doing more harm than good, the parent commenter doesn’t know.
The study doesn't show that donation is a good thing. Showing a miniscule reduction in blood markers is not the relevant variable - what you'd actually care about is: do I liver a longer or better life because of this intervention? There simply isn't any evidence that a tiny reduction in PFAS from blood donation results in any improvement in any clinical outcomes. Because we don't know either way, it's also possible that there would be harms from this - as blood donation is not entirely risk free, exposing people to syncope while driving after giving blood, skin complications like infections, or other rare issues we don't even know about.
And from what I understand, PFA contamination has no bearing on whether or not you can donate.