Do you drive a car? Do you fly in airplanes? Do you use electricity? Basically, as TinyEve eluded to, unless you live in a cave and make a living by fishing and growing your own organic food, you also have a hand in the destruction of the Ozone layer. I would venture to say that you haven't a clue as to what effect cigarette smoke actually has on the ozone layer anyway. Don't become an anti-smoker because of environmental reasons...that's just silly.