beside household dust, if you don't prewash your fabric you are also drawing in a lot of chemicals. I used to part out quilters estates on ebay, and I learned early on the profit on stashes wasn't worth the breathing problems working with the fabric gave me.
You might also consider having a duct cleaner service in. This house had never had it done until 2 years ago, and it did help a lot. Then we turned around and put in a new bathroom. Still dealing with sheetrock dust
