Second, the mold spores must have a source of food to grow on. Mold can grow on a variety of household substances, from rotting fruit and vegetables to wooden panels or fabrics. Mold is sometimes found growing on inorganic substances like plastic or steel. When this happens, the mold is still feeding on an organic substance that is on its surface, such as the oil leftover from a person’s fingerprints, organic fibers or residue from an organic cleaning substance.
Light is not one of the key resources mold needs to grow. This is because, unlike plants, mold is not photosynthetic and doesn’t use light to generate energy. In fact, light from the sun can inhibit mold growth and even kill it, so many molds thrive and grow better in dark environments.
Mold is a fungus that exists both indoors and outdoors, but not all molds are toxic. Many are harmful, but only a few types of mold can cause potentially serious injury. Most simply cause symptoms similar to those of seasonal allergies. Some, however, can cause more serious illnesses, such as pulmonary edema, brain damage, and emphysema. In some case of prolonged exposure, death may result. The common indoor molds are Cladosporium, Aspergillus, Stachybotrys, Fusarium, Penicillium, and Alternaria.