Why is it that some people die after 10 years of smoking, others after 20 and still others live a long happy life?

Genes + luck: You can't predict what will happen to a person with a risk like smoking, but we know there's no safe level of smoking. The chance of heart attacks, cancer and chronic problems increases the earlier you start, the longer you smoke, the more you smoke. Combining tobacco and alcohol causes mouth cancer. Info at http://betobaccofree.Hhs.Gov/health-effects/index.Html.