I never smoked - ever - anything. Didn't see the sense of putting rolled up leaves in my mouth & setting fire to them, especially if they contained a chemical we once used as a liquidinsecticide (nicotine.)
Tobacco also contains Polonium-210, a radioisotope that is known to cause lunc cancer when inhaled. The tobacco plant picks it up from the mined phosphate fertilizers used for growing them Phosphate deposits are often found in proximity to uranium & its decay products.
I think we worked this out at work. Was a while ago and the numbers are probably a bit hazy, but you'd need to hit something like eighty espressos in a half hour period to kill you. Reality of it is that you'd be unable to actually drink that much coffee no matter how hard you tried, and would likely start vomiting long before that amount.