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.
A crucial guideline in Scrum is that five to ten percent of every Sprint must be dedicated to Product Backlog Refinement A crucial guideline in Scrum is that five to ten percent of every Sprint must be dedicated to Product Backlog Refinement is not for PBIs selected for the current Sprint; it is for items in future Sprints. A good practice is to have at least two Sprints worth of work ready to go in the Product Backlog.