To clarify, there are two laws about this. There is a specific law (I'm not sure if it's just in NSW or if it's nation-wide) about not being allowed to smoke w

To clarify, there are two laws about this. There is a specific law (I'm not sure if it's just in NSW or if it's nation-wide) about not being allowed to smoke within 4 meters of an exit to a building (because smokers tended to smoke right outside a building -- presumably because it's more convenient -- when indoor smoking became illegal). A large cluster of people smoking in front of a doorway is not much better than those same people just smoking in the lobby (and people who need to enter the building can't really avoid it). There are other laws about smoke-free areas (my university campus is one of them). As a non-smoker I do appreciate this quite a bit (having lived in a country where smoking in public areas and indoors was very common), but I'm not sure about whether it is actually a significant improvement for non-smokers. The city's image is probably just as significant a motivator for such rules. Regarding data, I did a quick Google search and found some articles[1,2,3] ranging in dates to 2007. I've only skimmed them, but one of them[1] specifically mentions doing comparison to pollution from cars. [1]: http://erj.ersjournals.com/content/early/2016/05/26/13993003.00064-2016 http://erj.ersjournals.com/content/early/2016/05/26/13993003... [2]: https://news.stanford.edu/news/2007/may9/smoking-050907.html https://news.stanford.edu/news/2007/may9/smoking-050907.html [3]: https://www.sciencedaily.com/releases/2009/11/091118154619.htm https://www.sciencedaily.com/releases/2009/11/091118154619.h...