It is very common for ex -smokers to become significantly more sensitive to tobacco smoke, and lingering odours. As an ex-smoker I am NEVER tempted to smoke (tobacco) again, and one of the reasons is actually the incredibly bad reaction I get to smoke and burnt tobacco odour. It has nothing to do with temptation, The reaction is not purely psychological: I have had some rather uncomfortable physical reactions-akin to allergic reactions- o smoky environments when I can't escape relatively quickly. In the past I was a heavy smoker and able to tolerate very poor air quality without reaction, now I can tolerate smoke much less than the average non-smoker. I am, however, quite unsure of the reason, but don't doubt that it has some physiological basis atleast partially. Smoking is a particularly challenging issues of freedom and ethics, especially in public places, however it is considerate for the smoker to remove themselves atleast to an unconfined space, and away from the entrances of businesses for example, to avoid inflicting their habit on others. Second-hand smoke is always unpleasant and harmful to non-smokers and the considerate and morally concerned smoker should atleast be concerned with minimizing these impacts. The real answer is, of course, to stop smoking as tobacco cultivation and use is a fantastic drain on the environment, human society and one's own family, but no one expects everyone to quit tobacco just like it will be a long, hard struggle to eliminate crack/cocaine, heroin and methamphetamine from social use.

On the other hand, even that is not really adequate when it comes down to walking across a busy street at night, filled with bars, pubs and clubs (hence many smokers standing outside) and I fully support the creation of well ventilated, interior smoking areas in public buildings and businesses. Mindless ostracization of smokers is counterproductive for everyone, but a hermetically sealed, interior smoking area with air filters, might well serve public health much more effectively. This is something of the equivalent of a "safe injection site" for heroin users, and will probably prove itself given proper study.