What is that smell—is that mold?
Did you know that musty smell you associate with mold is actually from wet building materials, and not mold? Still, mold grows where there is moisture, so you still would probably find mold in wet building materials. Or wet insulation. Improperly installed plumbing. Window frames. Damp wall paper. We could go on. Mold belongs outdoors in its natural environment, although we do find mold indoors.
What you smell are what we call microbial volatile organic compounds (mVOCs). These odorous compounds, often described as musty or earthy odors, are often the first signal of mold growth. The mold may start releasing these compounds even before you can see any mold growth.
What kind of mold you would find in your house?
It is quite rare to find stachybotrys, which is considered “black mold,” in your house.
Molds are fungi that grow on moist, warm organic matter. Though there is over 100,000 species of mold, there are only 4 genus of mold that are commonly found indoors. Here’s a rundown:
Alternaria is a normal agent of decay and decomposition. It can grow thick colonies which are usually green, grey, or black. You may find it where water condenses on window frames, bad shower installations, or the drip pan of an AC unit. The fungi may grow on skin and mucous membranes (like the eyeballs), or within the respiratory tract.
You might find the green, grey, or black growth of Aspergillus in your house on damp walls, wallpaper, drywall, carpet and mattress dust, upholstered-furniture dust, HVAC insulation, furnace filters and fans, humidifier water, and decomposing wood. For folks with weakened immune systems, breathing in Aspergillus spores can cause an infection in the lungs or sinuses which can spread to other parts of the body, and may include hearing problems or even hearing loss. (A species of Aspergillus is used to make sake. Who thinks of this stuff?)
Alternaria, and aspergillus are those molds typically found seeking breeding ground in your home. Aspergillus may be mistaken for the black mold stachybotrys.
Cladosporium likes to live in wet corners, along the caulking or on the tiles in your shower or bath, on shower curtains, in insulation, window frames. Similar to the other molds we’re talking about here, it’s white, grey, green, or black. The airborne spores of Cladosporium species may cause infections in the sinuses and lungs, or skin and toenails.
It may be the green fuzzy stuff you’ll find on a sandwich, or on paint, in carpet, wallpaper, interior fiberglass duct installation. If penicillium sounds familiar, some members of this genus are used to produce penicillin. Other species are used in cheesemaking, but don’t try it at home. There are like, 200 species of penicillium, so it’s kinda hard to track the exact species down for your next homemade batch of Camembert.)
Common symptoms of mold allergies include skin irritation, eye irritation, wheezing, and nasal stuffiness which most of us —unfortunately— experience as allergy symptoms that show up with spring weather. Immune-compromised people and people with chronic lung illnesses, such as obstructive lung disease, may get serious infections in their lungs when they are exposed to mold. Mold does not react the same with everyone, so some may experience little or no symptoms, while others have severe reactions.
So, if you think you have it, and you can feel it, what’s next.