Yes it still harmful because it is air pollution to your lungs. My kid's pediatrician used to tell me that I should change my clothes after smoking a cigarette and before I carry my baby.
In Scrum, a product backlog item (PBI, backlog item, or item) is a unit of work small enough to be completed by a team in one Sprint iteration. Backlog items are decomposed into one or more tasks. See also backlog effort estimation unit.
PNF is an acronym for proprioceptive neuromuscular facilitation. It is not really a type of stretching but is a technique of combining passive stretching (see section Passive Stretching) and isometric stretching (see section Isometric Stretching) in order to achieve maximum static flexibility.