Just because you find a ham or lunchmeat, or bacon, or other cured meat, that says "no nitrates added", or "naturally cured", it doesn't mean there are no nitrates. They add natural nitrates, usually found in celery seed, and sometimes those naturally cured meats have more nitrates than the ones which the chemical is added to! So if you are sensitive to nitrates and nitrites, beware - those will also have them.
Serrano and Parma hams are supposedly cured with just salt, but I haven't seen any tests done on the meats, to see if nitrates were in them. Maybe they add some natural source?