Mold can grow in almost any environment and thrives on a number of common surfaces. All that mold need to exist is moisture and a source of food. It is reproduced when spores are released into the air. Penicillium, or “bread mold”, Stachybotrys, Alternaria and Cladosporium are the most common forms of mold found indoors. Exposure to mold and mold spores can cause allergies and hay fever to be aggravated even in the non-toxic forms. In addition, mold secretes an enzyme that can break down building materials over time. The cellulose fibers in materials like wood and ceiling tiles can be damaged as well as the paper covering that encloses the gypsum in drywall.