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Mold Exposure

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Medical Author:

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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Medical Editor:

William C. Shiel Jr., MD, FACP, FACR

William C. Shiel Jr., MD, FACP, FACR

Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

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What is mold?

Mold refers to multiple types of fungi that grow in filaments and reproduce by forming spores. The term "mildew" is sometimes used to refer to some kinds of mold, particularly mold with a white or grayish color or mold growing in shower stalls and bathrooms. Mold may grow indoors or outdoors and thrives in damp, warm, and humid environments. Mold can be found in essentially any environment or season.

The most common types of mold that are found indoors include Cladosporium, Penicillium, Alternaria, and Aspergillus. Stachybotrys chartarum (also known as Stachybotrys atra and sometimes referred to as "black mold") is a greenish-black mold that can also be found indoors. Stachybotrys grows on household surfaces that have high cellulose content, such as wood, fiberboard, gypsum board, paper, dust, and lint.

Molds reproduce by forming tiny spores that not visible to the naked eye. Mold spores are very hardy and can survive under conditions in which mold cannot grow, such as in dry and harsh environments. These spores travel through outdoor and indoor air. When mold spores land on a surface where moisture is present, mold can start to grow.

Outdoors, molds play a role in the decomposition of organic matter such as dead trees, compost, and leaves. They are most common in damp, dark areas or areas of decomposing plant life. Indoors, mold is often found in basements or shower stalls. Indoor mold has the potential to cause health problems and can destroy surfaces and objects where it grows.

Where can mold be found in homes?

Although shower stalls and basements are typical moist areas prone to the growth of molds, any moist area in the home may harbor mold. Drywall, ceiling tiles, carpets, furniture, ductwork, roofing, paneling, wallpaper, and the areas around plumbing pipes are examples of areas in the home that may become infested by mold if the requisite growing conditions are present.

Mold from the outdoors can enter the home through open doors, windows, and vents. It may also become attached to clothing, shoes, and pets and therefore be carried indoors.

Mold can have many different colors and sometimes appears as spots. Additionally, a musty odor may be present. Mold growth may also be hidden underneath carpeting, on the back side of wallpaper, and behind drywall or paneling.