Aspergillus, Cladosporium and Stachybotrys are some common types of mold present in and around homes. Some molds are innocuous and only aesthetically unpleasant, while others cause illnesses and allergies.
Aspergillus exists indoors and outdoors. Indoors, it causes problems when it grows in vents or air conditioners. Many people breathe aspergillus in without ill effect but for others it is a major allergen. This fungus also causes a lung infection known as aspergillosis and is capable of spreading to other organs.
Cladosporium is black or green in color and commonly grows behind toilets and in air ducts, especially if the surfaces are damp. Cladosporium is typically innocuous but sometimes causes a rash, dry eyes or sore throat. In rare cases, it causes sinus and even brain infections. This fungus is one of the species responsible for fungal meningitis.
Stachybotrys is another green or black fungus. It is less common that aspergillus or cladosporium, but thrives on cellulose, making wet ceiling tiles, wood or drywall an excellent habitat. Stachybotrys affects skin, sinuses, eyes and lungs. In rare cases of high contamination over long periods of times, it causes a serious pulmonary infection in very young infants that leads to hemorrhaging of the lungs.