Smoking. I can't think of a single positive one. If you do not smoke do not start.If you do quit.
Expense, death. About 50% of teen smokers will continue to smoke as adults. About 1 in 3 adult smokers will die as direct result of their smoking; many others will have significant health problems. Smoking sickens you and the people around you. Cigarettes are expensive and make you stink and die young with crinkly ugly leathery skin. Enough?
Teen smoking. Susceptibility to respiratory tract infection, precursor to other habits, bad smell, compromising immune system, all but a few of the many negative effects of nicotine.