On the other hand, dust mites like polyurethane foam. They like it a lot. It has an open-cell honeycomb structure that provides a perfect apartment complex for mites to live in. Every time you move on top of polyurethane foam, you compress this sponge like material, as it expands to its original shape, it sucks in dust, old skin, moisture or whatever. It's like a little dust mite city with automatic food delivery.
Most companies use polyurethane foam in their mattresses, especially in pillowtops .
We don't use any poly-foam for added plushness in our better beds. Instead, we use wool. We suggest sunning your mattress-top a couple of times a year. Sunning will kill dust mites. Latex and visco-elastic are both dust mite resistant.