Active smoking also harms our children. If a pregnant women smokes, her child is far more likely to be of low birth weight and to be born prematurely. Both of these conditions can cause a variety of heath problems, both acute and chronic. Active smoking is also harmful to children because it gives them the very clear message that it is OK to smoke. Do as I say, not as I do didn't work very well when I was a child and it does not fly very well today either.
Active smoking is only part of the danger.
There is passive smoking as well. For years, people were concerned that passive smoking was hazardous to non smokers, but there was no proof. Those days are over. Proof is abundant that passive smoking causes increased rates of heart attacks and cancer in the family members of smokers, even if they themselves never smoke. It has been shown that nicotine is present in substantial concentration in breast milk if anyone in the house smokes, even if the nursing mother does not.