Unless you clean your home on a regular basis, the clutter gathers dust. When you have piles of “stuff” you are not likely to move them in order to clean. This accumulated dust can cause lung irritation and allergy flair ups. Stacks of boxes that block vents also cause poor air circulation and lack of filtering the air. I’ve also unpacked boxes of papers that have been stored so long there was evidence of black mold on the papers or books. You certainly don’t want to breathe