I Feel Wife Chooses Cigarettes Over Me, She Hides It

I feel wife chooses cigarettes over me, she hides it and acts like I am stupid. she thinks I cannot smell it, she smokes at work and when we have separate days off, which is most of the time. I think she schedules herself separate days off from me just so she can smoke. I have seen far too many people die from the effects of smoking and I can't stand it. When we married 16 yrs ago she quit because I said I did not want to be married to a smoker. I believe she has smoked the whole time and has hid it from me, I have always caught her doing it.