Save me from poisioning!

Hello, smart people on the Internet! I know there is a nutritionist-in-training, and a spouse-of-an-epidemiologist, out there, as well as people who can pluralize Latin and do fancy maths, so maybe someone can help me. I just bought a new copper teakettle off The Ebay, and found out (today when I got it) that it is unlined. I hadn't thought of that, so I did a little research and determined that unlined copper could kill me dead if I cook with it. However, that seems to be in the context of unlined copper cooking pans, as copper can react with acidic foods. Unlined copper in fact seems to be advised for certain uses (like melting sugar for caramel), and in this case I would only be boiling water in it.

So: if I use my unlined copper teakettle for boiling water, how much will it hasten my death? Any ideas? Or should I just use it for making caramel?