Cigarette smoke can be difficult for people with respiratory problems to deal with. Even when it's outdoors.
Just poking fun. Don't get nervous. :)
So can perfume, and the smell of peanuts to those with peanut allergies. So the question becomes: whose responsibility is it to deal with situation? The person who has the problem? Or is it the responsibility of everyone else in the whole world to make sure they're not producing smoke, wearing perfume, eating peanuts, etc., etc., etc., etc. in public (or even in their own apartments)?