as well as smoking (very rarely since we do not know yet how that can affect each individual person, but collectively for the most part it does more harm than help)
I'm assuming that you are talking about smoking tobacco.
One of my major issues with people smoking tobacco, having encountered a 100% additive free cigarette which I deigned to try because of that quality, is that most people do not go out of the way to minimize the harmfulness of their smoking by being picky about what types of cigarettes or cigars that they smoke. They just seem mostly careless about it. And if one is going to do something that has the potential to harm one's body, I think being careless about it very much harms the moral integrity of the action.