Just another thought.... Have you considered venting out the room after you vape? So the room you vape in isnt full of second hand vapors. This question also leads me to wonder if when you combust, do you do it outdoors, hence better ventilation? When I got my wisdom teeth pulled before I put a trash bag over my head and filled it up so that I could just breathe in vapors like room air. This was not the smoothest method. It really bothered my nose like as if I had just smelled some pepper. All this leads me to wonder if vapors from mouth straight to lungs are okay but through the nose and sinuses are not okay. Also, is it possible that the added suction pressure needed for water pipes to work, can exacerbate asthma problems?