None, thank goodness. We have some neighbors that are practically chain smokers. She is a SAHM and every 15-30 minutes like clockwork she is out smoking. I'm not sure how many packs that must be per day. Her husband is about the same once he gets home. She has the nastiest cough while she smokes, to the point of coughing up several times, which is probably not a good sign. Frustrating for us as it blows over occasionally.