Mold is a natural part of the environment and can be found all around us, but having mold growing indoors and exposing people to high levels in the air we breathe can lead to serious health concerns.

Inhalation exposure to mold indoors can cause health effects in some people. Molds produce allergens, irritants, and, in some cases, toxic substances known as mycotoxins.

Inhaling or touching mold or mold spores may cause allergic reactions in sensitive individuals and the mold does not have to be alive to cause an allergic reaction. This is why it is important to minimize people's exposure to mold, even after it is no longer alive.

Allergic reactions to mold are common and can be immediate or delayed. Repeated or single exposure to mold, mold spores, or mold fragments may cause nonsensitive individuals to become sensitive to mold, and repeated exposure has the potential to increase sensitivity.

Exposure to mold can even trigger asthma attacks in people with asthma who are allergic to mold. As an irritant, mold can irritate people's eyes, skin, nose, throat, and lungs of individuals whether or not they are allergic to mold.

Breathing in mold may also cause hypersensitivity pneumonitis, a disease that resembles bacterial pneumonia. In addition, exposure to certain types of mold, such as Aspergillus, may result in opportunistic infections in persons whose immune systems are weakened or suppressed.