A new study finds that tattoo removal is less likely to succeed if the person is a smoker. Smoking can reduce by 70% the chance of successfully removing a tattoo after 10 treatment sessions. Smoking is believed to hinder tattoo removal because smoking is known to hinder wound healing. The research was conducted at a laser-surgery center in Milan, Italy, from 1995 through 2010. There were 352 people in the study, of which 201 were men, with a median age of 30 years old.