To prevent mildew from forming in your refrigerator, wipe the inside with vinegar. The acid effectively kills mildew fungus. Place doormats inside your entryways as well as outside your doors to reduce the amount of outside dirt that gets tracked in. Throw away piles of newspaper, clean up any food crumbs and fix continuous water sources such as leaky faucets and pipe condensation. These are attractions to cockroaches.
Cockroach debris is a strong allergen.
Clean your air conditioner and change the filter according to the manufacturer's directions. Mold thrives in cooling systems and pollen gets trapped in the filters.