Really? I have heard of alot of FUD around plassing in particular, see e.g. https://www.theatlantic.com/health/archive/2014/05/blood-mon... / https://archive.is/kXRef

Lowers heavy metals or something

I'm not an expert but it seems it also lowers PFAs.

> In this randomized clinical trial of 285 firefighters, both blood and plasma donations resulted in significantly lower PFAS levels than observation alone. Plasma donation was the most effective intervention, reducing mean serum perfluorooctane sulfonate levels by 2.9 ng/mL compared with a 1.1-ng/mL reduction with blood donation, a significant difference; similar changes were seen with other PFASs.

https://pmc.ncbi.nlm.nih.gov/articles/PMC8994130/