Sure, a little dust might not harm your items, but there are ways to minimize the effects of dust on your stored items. If storing an item or piece of furniture with fabric, mattress or furniture covers over your items will protect them from damaging dust. If a mattress cover is unavailable, two fitted sheets over a mattress or a box spring will do in a pinch, protecting your bed from dust and dirt.
When storing wooden furniture, a fresh coat of furniture polish will moisturize the wood and help to repel dust and dirt. Likewise, to prevent rust from metal items, a good wipe down and lubrication with oil should keep the rust at bay.