I know you don't want to hear this, but coming from an ex smoker, you should try your best to quit. It is the hardest thing I've ever done. I still crave sometimes, and probably will forever. I will tell you aside from the "not dying" aspect(lol right?) I have noticed an improvement in the gym in both aerobic and anaerobic exercise.
I know it didn't answer your question the way you wanted, but if you truly are worried about health that is the best option. Cigarettes are horrible enough alone.