A collection of photographs of mold that were taken inside buildings that had varying levels of contamination. The mold pictures shown vary in color, texture, shape and pattern. Some species of mold pictured can be harmful to humans when inhaled. Others may cause mild to severe allergies in some. Most mold types can be very harmful in high airborne concentrations to those with immune systems that are developing (children) or that have been weakened due to diseases such as HIV-AIDS or cancer (from the cancer or from chemotherapy), or the elderly.