Mold are a types of fungus. It is present almost everywhere, including the air. In general, normal amounts of mold in the environment do not pose a substantial health risk to healthy people with regular immune system function. There is no single type of mold called “black mold” — many molds are black. When people use the term, they may be referring to a type called Stachybotrys chartarum (S. chartarum), also known as Stachybotrys atra. There is no scientific evidence to suggest that exposure to S. chartarum is more dangerous than exposure to any other type of mold. However, some people may be more sensitive to mold spores than others, and they may develop respiratory symptoms after inhaling even a small number of spores. In large quantities, mold spores can cause ill health in almost anyone. Therefore, people should remove any mold growth in the home and take steps to prevent it from growing back.
Studies have shown that people who are atopic (sensitive), already suffer from allergies, asthma, or compromised immune systems and occupy damp or moldy buildings are at an increased risk of health problems such as inflammatory and toxic responses to mold spores, metabolites and other components. The most common health problem is an allergic reaction. Other problems are respiratory and/or immune system responses including respiratory symptoms, respiratory infections, exacerbation of asthma, and rarely hypersensitivity pneumonitis, allergic alveolitis, chronic rhinosinusitis and allergic fungal sinusitis. Severe reactions are rare but possible. A person's reaction to mold depends on their sensitivity and other health conditions, the amount of mold present, length of exposure, and the type of mold or mold products.