Both our indoor and outdoor environment have mold spores present. There is no such configuration as a mold free environment in the Earth's biosphere.
Food sources for molds in buildings include cellulose-based materials, such as wood, cardboard, and the analysis facing on Mold Inspection Palm Beach both sides of drywall, and all other kinds of animate matter, such as soap, ashes and fabrics. Carpet contains cinders false of organic matter such as skin cells. If a house bomb mold, the moisture may be from the basement or crawl space, a leaking roof, or a leak in plumbing pipes behind the walls. Insufficient ventilation can further enable moisture build-up. The further people in a space, the more humidity builds up. This is from normal breathing and perspiring. Visible mold colonies may figure where ventilation is poorest, and on perimeter walls, because they are coolest, thus closest to the dew point.