Depends where that air is. In Minnesota, we have laws that ban smoking in public buildings and they are pushing to pass laws to make it so you can't smoke on public property that is outdoors as well. If that air is in a building that is owned by someone other than yourself, then no, you don't. The property owner can choose to do what they want with their building and can allow patrons to smoke or ban smoking on the premises if they so desire. You are not required by law to enter those places and thus can choose whether to go or not to go.
You can do that and the owner of that restaurant can decide to let you stay or kick you out. Perhaps if spraying pesticide in the air was a common social activity there would in fact be both pesticide and non-pesticide sections in restaurants. The reason that restaurants made those accommodations (at least in the past, before the recent smoking bans) is that a restaurant is like any other business and the owner wants to profit off of both smokers and non-smokers alike. However, I feel that society has changed quite a bit in past 10 years in regards to this issue and I wouldn't be surprised if businesses would just outright ban smoking on the premises since the majority of clientele would prefer to go a business which bans smoking rather than one that does not.
I only occasional smoke a pipe or cigars, so the issue does not affect me that much directly in regards to being able to smoke in doors at restaurants/bars/etc. However,the United States is a republic and has property rights, therefore, government has no right to tell those bars/restaurants/wherever whether smoking can or can't be allowed on their property. Society can do that by merely choosing to do business elsewhere.
