http://bmj.bmjjournals.com/cgi/content/full/331/7527/1228-d?etoc
"Doctors and other staff working in prisons would face a greater risk of assault if smoking were to be banned in that environment, the head of the prison service has told MPs. Phil Wheatley, director general of the Prison Service told the health select committee inquiry into smoking in public places last week that a complete ban would have serious repercussions and create control problems for staff. "