What is Mold? Molds are a type of Fungi that produce long tube‐like structures called hyphae (pronounced Hi Fee). As the hyphae grow, they develop into hairy or fuzzy looking masses called “colonies.” Depending on the type of mold and growth conditions, colonies can have a wide variety of shapes, sizes, textures, and colors (black, dark olive, pink, white, green, bluish green, yellow, brown, light gray, dark gray, red, orange, or various shades of these colors). (BTW, there are many black molds, many of which are not the “toxic” variety; this will be addressed in another article). In addition to the hyphae, mold colonies can also contain tens of thousands of tiny structures called “spores.”
What are mold spores? Spores serve three important roles. First, they are the way molds reproduce. When conditions are right spores will germinate like plant seeds to produce new hyphae, and eventually new colonies. Next, spores help mold to survive under harsh conditions (e.g. extreme temperatures, lack of food, lack of moisture, etc). They are also the way molds are spread throughout nature. Since they are very small and light, spores can be carried for literally thousands of miles by wind and moisture droplets.
Where do molds come from and what do they need for growth? Molds can be found virtually everywhere in the world. Outdoors, molds are found in the soil, on plants, and on dead or decaying matter. They actually serve an important role in nature by decomposing complex materials (e.g. dead leaves, tree stumps, dead animals, etc.) into simpler “foods” that support other life forms. The most important requirements for mold growth are moist conditions, an organic food source (e.g. wood), and a suitable temperature. Most molds grow at temperatures that are comfortable for humans, but some can grow at more extreme temperatures, even near freezing.
How am I exposed to mold spores?Mold spores can enter a house/building through open doors, windows, air intake systems, holes in building envelopes, and/or water leaks. Spores can also be carried indoors on humans, insects, pets, and items brought in from the outdoors (e.g. outdoor furniture, firewood, etc.). It is normal, therefore, to have some mold indoors.
Problems can arise, however, when indoor conditions are suitable for the mold to grow and multiply. Plumbing leaks, basement floods, sink overflows, spills, roof leaks, excessively high humidity, high temperatures, and condensation are some of the common events/circumstances that can provide the moisture needed trigger mold growth. Under such conditions, mold spores can produce colonies in as little as 1 to 3 days. . The slightest disturbance of a mold colony can cause the sudden release of massive amounts of spores into the environment.
What are the consequences of mold growing indoors? If moisture problems are not addressed quickly, mold can have serious impact on the building’s structure, its contents, and its occupants. Actively growing mold, for example, can eat away at a building’s structures such as walls, ceilings, floors, windows, support beams, etc. It can also damage personal belongings including clothing, leather goods, books, cardboard boxes, and furnishings like carpeting, wallpaper, tapestries, sofas/upholstery, and furniture.
When excessive and persistent mold contamination exists indoors, occupants can become sensitized to mold and develop allergies and/or other medical conditions. Furthermore, elevated indoor mold conditions can potentially worsen the symptoms and overall health of individuals who have asthma, compromised immune systems, lung disease, or other serious medical problems. Even if the spores are dead and can no longer grow, they can still trigger allergies or other undesirable reactions.
The purpose of this article was to provide our readers with some fundamental information about mold, what it is, where it is found, how indoor occupants are exposed to mold, and some of the consequences of out‐of‐control, indoor mold growth. We hope it has served its purpose.
Dr. Mark Banner