When I was in federal prison and county jail, I seen guys get tattoos by burning triple antibiotic ointment as a candle and collecting the soot that built up to make ink - they would also burn plastic chess pieces - and also tattooed people with Badger Paint and other weird ****.
Humans are like cockroaches. You can go inject nasty **** into your arm every day and still live many decades - nothing really makes sense. Carcinogenic molecules, doesn't make sense - why doesn't every cigarette smoker develope cancer? Some people get cancer and never smoked before.
Forget all the science - the religious rules are basically 'do not scar or mark your bodies for the dead', something like that. I put more weight behind that than "all the ink is toxic and everybody is going to die."
I never had a single tattoo. I think is skips a generation. My parents are tagged up all over. It just was not something I ever desired - except when I wanted glow in the dark veins and an artist told me he would have to do it after hours since the ink was not legally sanctioned or whatever - but guess what - it could be very toxic and some people die tomorrow and other people go on to push 100 years old just drinking the **** like Ovaltine and taking daily baths in it for skin care.
I don't mean to dispell any alarm or lead people into a false sense of security - toxic **** is toxic. I just don't think this is as big of a deal as maybe it is made out to be here. Humans for generations have been doing even worse crazy **** to their bodies with sometimes barely any consequence - we are incredibly resilient and all of our data is chock full of 'well, this person should have died but uh... Turns out you don't need most of your brain.'
For chemicals in general, I look at how long Shulgin and Hoffman toiled the mortal coil. You could go inject an LD50 of bleach tomorrow based on your weight and you still might just survive it.