A lot of men and women in Myanmar are seen spitting red liquid on the streets. At first it seems like they are ill and that's blood, but soon it becomes clear that it is a result of chewing a betel nut.
Apart from other ingredients, the chewing set includes some kind of limestome, which grinds the teeth to a level where their width is equal to the spaces between them.
The fact that this obvious example does not deter others from starting up the habbit, makes me believe that commonly seen images of rotten lungs on cigarette packages won't do their job either.
"It can't happen to me" - isn't it what we usually like to think?