a) Empirical research would prove to one that any body foreign to our own is not nessecarily considered a threat. An IV is not considered a threat. In fact, most inorganics (glass, many metals, et cetera) are not perceived by the body much at all. Making such a broad statement is not useful because it is incorrect.
b) Your fact stating, "1 tattoo will give you a greater chance of cancer of the skin and blood than an entire lifetime in the sun without sunscrean"... do you have a link? Anything that backs this statement up? Preferably something from a medical journal rather than www . ihatetats . net.
c) Yes, my previous examples were digestive... it's what I had off the top of my head. Your arguments against mine are, however, not wholly correct. While the digestive system DOES have a great deal of protective measures, one can still die from sometimes a very SMALL amount of a truly
toxic substance, like
DEG (Diethylene Glycol, commonly used as
anti-freeze).
d) On your behalf, I found
this article. It discusses and outlines a few pigment colors, what commonly goes into them, and what some of the potential risks are. Don't mistake what I'm saying here.... ANYTHING can be risky. Getting a simple ear piercing could potentially lead to death (via infections and the like). Caution is always warranted, but paranoia is generally not.
e) Read
this before anyone makes a decision. This article pertains to what we are discussing, but the whole site has a slew of good information.
Once again, I would not argue that tattoos are 100% safe 100% of the time. If you go to a reputable "ink slinger" who has been around a while, chances are bad inks would've closed them long ago. Certain colors are better than others. Reds are a possible issue. If you REALLY want reds, talk to your artist. If they refuse to tell you what's in it, go somewhere else. It's an open market after all.
*EDIT for spelling