We ended up using India ink, which (according to the encyclopedia of ink* ) is mainly soot.
We were able to isolate it in the HPLC and through some histopath experiments show that it didn’t have any negative local effect between (IIRC) seven and 60 days. Why those times? Protocol was to tattoo on day 0, wait a week for the site to recover, then inject our experimental material on day 7, sacrificing subject animals at D14 (one week), 21, 28, 35, 42, 49, and 56 days.
I don’t think lamp black is really a good idea, but was adequate for our purposes. We didn’t have to do any kind of long term study, just demonstrate that it would not interfere with our work in guinea pigs.
* I actually went to a specialist art store and the owner did indeed go to the back of the store and pull out one of the volumes of a multi-volume work on inks and pigments! I don’t know if it was actually named “The Encyclopedia of Ink”, though I do remember that that’s how he referred to it. He just photocopied the relevant page for me, most of which was the entry for India ink.
But soot is carcinogenic, no? And with soot consisting of nanoparticles small enough to cross the blood-brain barrier, I can imagine a chance of soot-based tattoo substances diffusing into the brain.
But, as with anything, it’s about nuance. You can read through the ingredients here[0] and tell me what you’d like in your body.
The earliest tattoos, from my understanding, were done by incision and rubbing carbon into the wound. Regardless if you use old or new inks/techniques, it’s not really cut and dry to say “this is bad/good” because the size of the particulates matter. For a tattoo shop that uses high quality ink, and is diligent in its sterilization, most inks are fine. The large molecules are “trapped” by your immune system to just stay there[1], making them not dangerous.
There is a ton of research on PubMed about tattoos, most being negative. However, I suspect it’s because the authors had a predisposition to be negative from the start based on how the research is conducted and what they focus on. But I could be wrong and you should make up your own mind.
Bottom line: if you get tattoos, pay the premium and go to a good shop. The hygiene and good products are worth it, if that’s your thing.
Why not? We tattoo all sorts of food animals, which is what they were originally bred for (and I can confirm from experience that they are yummy — they are street food in the Andes).
Not that I have eaten the ones bred for medical research. But a fun side point: we did drug program for which the FDA insisted that preclinical studies be done in mini pigs (similar to human skin) though our research program had been in guinea pigs. The Göttingen mini pigs, like many experimental program animals, are carefully inbred so you can get a group that are genetically quite similar. We had to do the study in Toronto because the labs in California claimed they were being outbid by certain restaurants who wanted pork short ribs.
I was (and remain) convinced that this was some kind of racist joke (among other things these kinds of animals are quite expensive), but multiple people swore it was true.
So maybe you have eaten an animal intended for scientific research.
How things have changed. 30 years ago we said "please get your pets tattooed" because ear tattoos were how veterinarians reunited lost animals with their humans. Now we use RFID tags and tattooing is frowned upon.
