Comment by seethishat
4 hours ago
Doing whole blood donations seems to significantly reduce PFAS in the blood. Here's one paper:
https://jamanetwork.com/journals/jamanetworkopen/fullarticle...
Edit: This also helps others who are in accidents, car wrecks, have Cancer, etc. Yes, we pass on the PFAS to others, but the immediate need for blood is more urgent than the potential long term impacts of PFAS.
Bloodletting making a comeback? And having actual benefits this time?
There's kinda a significant difference between bloodletting and blood donation.
For starters, you're not supposed to donate blood when you're sick.
The other being the quantity. A donation is 1-2 pints. Wikipedia lists bloodletting as easily 3 pints [1].
[1]: https://en.wikipedia.org/wiki/Bloodletting#Use_in_the_1600s_...
Although PFAS is helping bloodletting make a comeback https://www.theguardian.com/uk-news/2025/jan/16/bloodletting...
It never went away; now they call it "therapeutic phlebotomy"
me to the plague doctors: we are SO back
I used to donate blood regularly but now that I'm in Japan they require me to be decently fluent in Japanese to "understand" the risks, despite having done it a bunch of times in other countries (and other medical procedures not requiring Japanese knowledge).
My girlfriend accidentally told the donation center she went to Mexico, and they banned her from donating for four years.
Apparently you'd only go to Mexico to eat brain tacos and share needles with cows. Surely there's a better way to filter out risky blood.
> Surely there's a better way to filter out risky blood
It's simple Bayesian probability. Blood tests have a relatively high error rate. Hep-B tests have a 6-12% false negative rate early in the disease, and Hep-C is 3-6% even later in the course of the disease. That's considered a "very low" false-negative rate for a blood test.
In Bayesian terms, blood tests don’t “screen” for a disease. They reduce the odds ratio of contaminated blood by a factor of 10 or so. But the ultimate odds still depends heavily on the prior odds—the prevalence of the disease in the donor population: https://en.wikipedia.org/wiki/Prior_probability. Even with testing, you can reduce the risk of contaminated blood by drawing blood from a pool of donors that has lower prevalence rate of diseases.
Yes... travel, tattoos, drug use and sexual behavior can and should disqualify a person from donating blood.
All of these things can mostly be tested. When I donated regularly in the UK after being in the southern US, they screen me for west nile virus but still take my blood and use it.
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With travel, I understand that there is a higher risk of lots of diseases, and testing against all possible infectious diseases is not feasible. Drug use is also obviously disqualifying. But why would you care about someone's sexual behavior? The blood must be tested for common drugs and common blood borne diseases regardless, and it's perfectly possible to engage in sexually risky behaviors and not have any venereal disease (unlike with drug use, where it implicitly means you will have levels of those drugs in your blood), just like it's possible to be very careful with your sexual behavior and still get a disease.
Note: for tattoos, I have no idea if the problem is also related to venereal diseases, or if there is any problem from contamination with the tattoo ink itself, and I don't care enough about this subject to look it up.
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Well, it's the having of an infectious blood borne thing that disqualifies you.
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People have more unprotected, regrettable sex during travel and vacations, so maybe they're on to something?
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I don't get the sense we have any standards for actually vetting the blood that's donated, which is deeply concerning
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I was banned roughly the same time for being in the US. I guess its mostly so they don't need to check for unexpected things.
I get it, just seems like it could be more granular, especially since she could have just said no.
> eat brain tacos
What's wrong with that? Animal brains are a common dish in many countries, including France, Asia, and parts of the United States
Vector for prion disease.
There are other ways she can donate her blood.
"Accidentally"? Implying she should've lied about it even though they probably have some reason (evaluating risk presumably) for asking?
Let's say a year ago, you walked across a bridge in Mexico for five minutes to see if it's true that Mexico has a yellowish haze like in the movies. Oh, it doesn't. Then you walked back to Texas.
A year later, you go to a blood donation center and they ask you: "Did you go to Mexico in the last N years?"
If you say "Yes", you are banned for four years. If you say "No", you donate liters of blood over the next four years.
If you were in this exact situation, how would you weight which answer is better?
Sounds like a wild party.
I wonder what it would cost in the US to have a pint of blood taken - I can't donate. Guess I could do it myself...
I'm not sure there are any regulations around opting to do that in the US. Do you have a phlebotomist friend? If so, they might do it for you, but it can be risky and they might not want to take the risk, get sued, etc.
It is an interesting question. Are there companies that draw and discard?
> we pass the PFAS to others
Is there no way to filter them out of withdrawn blood?
That's correct.
Do blook banks have a way of filtering out PFAS? Or are we giving each other forever chemicals through blood donations?
A life saving blood transfusion or avoid forever chemicals likely already in my body, hmmm what to choose...
But does it have to be one or the other? Or is there some possibility of somehow removing the PFAS from donated blood?
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Not without filtering other things we need.
Aren’t we just donating the PFAS to potentially sicker patients?
I'd assume donated blood matches the average level that people already have in them, so not sure it really matters. But if you donated regularly enough, you could be donating blood that has lower than average levels!
PFAS doesn't immediately harm you like missing a few pints of blood does.
And it's not like you're concentrating higher levels of PFAS into the recipient, they likely have the same average blood concentration levels as the donor does since we're all equally exposed to the same sources.
Reason #136 for why tech-bros need a blood boy to infuse from daily.