|This page in a nutshell: Smoking, or the use of other legal tobacco products, is not inherently important enough to mention and should not be included in biographical articles by default.|
That a person's tobacco habit or vice is verifiable, even having multiple available citations, does not mean this detail is important enough for inclusion in a Wikipedia article. Tobacco use has no relevance to most biographical articles.
When is an individual's smoking appropriate for inclusion?
Being a smoker would be relevant to his or her article if that person was otherwise identified with an anti-smoking campaign and denied smoking, or is directly involved in activities with the tobacco industry. One's personal vices do not necessarily mean one should not advise others not to engage in them, but blatant lying about them would be important.
A possible example is when a subject dies from a smoking related illness. The article Andreas Katsulas is a good case. In that cause of death is deemed noteworthy, the effect of smoking on the health and eventual demise of a subject may therefore be valid if the subject died young or had their career otherwise shortened. The link between smoking and ill health must be made in the text, with citations or references, and not be an assumption by the editor.
Another example would be when one of a person's important traits includes being a smoker, in that it is part of their image and are identifiable by being smokers – Denis Leary, for example. In other words, if tobacco was enough of a part of one's life to be recognizable to the general public, then it merits inclusion in the article.