Back in the 50s, a cigarette with a pint, or during your lunch break, was the obvious way to relax - but no one knew then what it would lead to. For many smoking has now become a pernicious habit, with potentially fatal consequences. On No Smoking Day 1991, QED talks to life-long smokers, and with extraordinary film taken inside a smoker's body, takes a compelling look at how a moment's pleasure leaves its mark on human flesh.