The facts that cigarette is dirty and smoking is not permissible, do not necessarily make cigarette a wudu breaker. As it is expressed in the verse “…But if you are ill or on a journey or one of you comes from the place of relieving himself or you have contacted women and do not find water, then seek clean earth and wipe over your faces and hands with it…” (Al-Ma’ida/ The Feast 5:6), wudu is not broken by the things entering the body, but by the ones getting out at the relieving place. Smoking does not break wudu.
The same ruling applies for the people who drink intoxicants which are haraam (forbidden) and who touch or eat forbidden things. Although these are haraam, they are not wudu breakers.