But the flip side of that is that when smoke wafts into non-smoking areas, as it often does, it affects the non-smokers in ways that the policy is specifically designed to avoid. HKG has an interesting approach to this. There is no smoking in the airport except in specifically designated smoking rooms, or pods, throughout the airport. These rooms have glass walls, and it's amazing how much smoke there is in them. Equally amazing is the air filtration system that seems to prevent completely any scent of smoke from reaching the outside.