People who believe they have mold growing in their home may not know why it's there, but they do typically understand that exposure to elevated levels of mold indoors is not healthy.
Molds are organisms that may be found indoors and outdoors. They are part of the natural environment and play an important role in the environment by breaking down and digesting organic material.
Molds can multiply by producing microscopic spores, these spores are so small they easily float through the air and can be carried for great distances by even the gentlest breezes.
Mold is not usually a problem indoors, unless mold spores have landed on a wet or damp spot and begun to grow indoors. Common sources of water or moisture include roof leaks, condensation due to high humidity or cold spots in a building, slow leaks in plumbing fixtures, humidification systems, sprinkler systems, and floods.
As molds grow they digest whatever they are growing on. Mold can cause cosmetic damage, such as stains, but unchecked mold growth can damage buildings and furnishings. Mold can rot wood, damage drywall, and eventually cause structural damage to buildings.
The potential human health effects of mold are a major concern. Allergic reactions to mold are common and can be immediate or delayed. Allergic responses include hay fever-like symptoms such as headache, sneezing, runny nose, red eyes, and skin rash (dermatitis). Molds can even cause asthma attacks in people with asthma who are allergic to mold. In addition, molds can irritate the eyes, skin, nose, throat, and lungs of individuals whether or not they are allergic to mold.
Some types of mold are also known to cause infections in people with weakened immune systems. Some of these infections can be fatal if not properly treated. Mycotoxins are yet another health concern, some types of mold produce toxic byproducts which are known to cause a variety of health effects.