Ah, I've used the Anglo-Australian spelling Aluminium (-ium).
Aluminium cans are made from aluminium sheets. These are coated with a wax
to help prevent the aluminium from leaching. This wax has breaks in its
surface, and so the aluminium leaches out anyhow. I recall it being worse in
acidic drinks such as colas. There was a scientific paper on it in the
Medical journal of Australia in the early 90's if anyone cares to look it up
on Medline etc.
Ben Balzer