They're basically saying: "Sure, you're passing the buck, but there's no evidence that your reduction in PFAS results in an increase of PFAS to the recipient. Because we haven't looked." and then calling that "Science".
But let do some simple math. Let's say I (and a dozen other donors) have 10ng/mL of PFAS in my system and a recipient has 5ng/mL. Assuming 20 pints of blood in a human for the rest of this word problem. Recipient requires a transfusion of 10 pints which happen to be sourced by those 12 donors, What is their PFAS load after the transfusion?
˥ɯ/ƃuϛ˙ㄥ :ɹǝʍsu∀