If you're thinking about smoking or are smoking, take it from someone who's an expert on tobacco.  I was involved in tobacco production from the time  wore diapers.  My ancestors actually grew it in North Carolina before Columbus landed.  Practically every adult I knew smoked, chewed, and dipped it.  Until the 1950's, most tobacco was grown on small family plots and very few chemicals were used for insect and disease control. Until the 60's I had never heard of people dying from lung cancer.  Just ask your local county agents what's put in tobacco to make more money for the growers and cigarette companies.  I smoke an occasional cigar or pipe for the smell of the tobacco, but I don't inhale it on purpose because I can feel the effects of the smoke immediately.  I could make a list of over 100 smokers that I have known that have died of lung cancer.  When I was in college I worked in the horticultural greenhouse and we used canned nicotine as a pesticide.  It was highly corrosive to the metal cans and human tissue - and similar to prussic acid.  It was so deadly it was outlawed - it's scary that you can still put it in your lungs legally.  You have to be extremely addicted, suicidal, or ignorant of chemistry if you inhale tobacco on purpose.