It truly saddens me to see so many people here supporting this kind of laws, and even asking for more... As someone who doesn't consume tobacco, alcohol, marihuana, and even avoids using pharmaceutical drugs as much as possible, I'm all for personal choice. I'm no one to tell others how to live their lives, and I don't want others to tell me how to live mine. Live and let live.
I do agree of course that the right of others who want to avoid smoke should be respected (which includes me), but that's why there's laws against smoking in public places. This should be enough to balance both rights, and is certainly easier to enforce.
On a related (and anecdotal) note, my 62-year old father has been smoking for more than 40 years now every day, and he's fortunately one of the healthiest people I know. No cancer (despite his parents having it), no heart disease, no major surgeries so far. He does happen to have a very healthy diet, so there's that. No sugar at all for example... (should that be banned too ?) It just goes to show you though that these things are not black and white. That there's so many elements that determine a person's health that you can't just reduce it to one or two simple actions. And as someone mentioned before, pollution is probably responsible for far more damage to our lungs than we give it credit for... Specially on the big cities...
