This just reminded me of the conspiracy theory that TLR was hiding Atium in cans of food and stuff that was being sent off-world through the Pits perpendicularity, as a lining to the inside of the cans.
the tldr is that Atium is like a platinum group metal, and similar enough to tin visually that the inside can surface would be fairly indistinguishable from tin (plus with wherever the cans are going, people won't necessarily even know about Atium). So there's now a fortune's worth of Atium scattered throughout the Cosmere, hidden inside tin cans.
If i remember right, didn't Kaladin and the others eat from cans of food in Shadesmar? ...they might have actually been right there, holding some Atium, and didn't even know.
My memory could be wrong though, and this is of course a conspiracy theory (but there was a really solidly written reddit post about it...)