I don’t suppose anyone thought that banning smoking in enclosed public spaces would mean that the only place you are guaranteed to get smoke-free air is inside said public building: no longer can you nip outside for a “breath of fresh air” because many public buildings have to be approached through a haze of passive smoke.
Amongst the worst places for that are airports because people are often there for hours, and one of the worst of those, in my experience, is Luton because the ‘gauntlet’ there is a long ‘L’ shape and a good walk from the buses and car-parks. I can’t hold my breath that long, not walking and towing a case, anyway.