Yes, iron. You can clearly taste it. That's one of the things I noticed after using a plasmacutter to cut through sheet, the vaporized iron stays afloat long enough that if you take off your mask and get a whiff it smells like blood.
I was under the impression the iron in the blood was in the form of hemoglobin. Does hemoglobin itself have a metallic taste, or is the taste caused by something else in the blood?
Good question I do not know but I associate the two (blood, iron vapor) very closely. It may well be that the blood also contains some free iron but Iron is so toxic that I doubt that would be enough to taste directly so it may well that haemoglobin itself tastes metallic but it only has a handful of Iron atoms in it compared to a mountain of other stuff.
I've never bought the official explanation for this. We have just four iron atoms per hemoglobin. But the roughly quarter-billion of these per red blood cell are in the red blood cells, which presumably haven't all suddenly lysed and dumped their hemoglobin.
I think we should test with blood plasma first. I'm thinking it is the various salts in the plasma we're tasting, not the iron bound up in hemoglobin which is itself trapped inside of red blood cells.
