Can radon decay product levels spike with certain activities?
Yes. If radon gas levels are constant and an activity like smoking in the house or letting smoke from a fireplace spill into a room, there can be a sharp increase in the radon decay products suspended in the air. This is because the radon decay products will attach to these particles rather than preferentially be plated out on the walls, where they would no longer represent a risk. Even when this occurs, the radon decay products typically only go up to an equilibrium fraction of 50% (EPAs assumption). However, when the condition that caused the high particulate levels in the indoor air is corrected, the radon decay product levels quickly diminish to lower levels (within an hour). So bottom line, if you are concerned about risks from radon, dont smoke in the house (or dont smoke at all) and keep the air in your house free from high particulate levels. Note this is also where air filters can be a large help.
