(no my OC, I am attempting to help spread this that I saw first on https://programming.dev/post/33666663 because I think it helps to know that it is not too late to make changes even for major things like smoking and our health!)
One cig every 15 years would be less than all the second hand smoking and air particles you digest.
But "less than 1 or 2 packs a day" sounds it will definitely lead to health issues. I'd say 1 cig a day would be acceptable and probably without serious health issues.