Many homeowners have had the unfortunate experience of peeling back wallpaper, removing shingles or cleaning out the basement and discovering clumps of mold. The first reaction is often disgust, followed perhaps by fear that a mold outbreak will cause damage to the structure or serious health problems. Household mold can be a big problem, but it’s usually not as dire as many people fear.
How to detect mold
A type of fungus, molds come in many varieties and on different surfaces—some prefer old pieces of bread, some like drywall. They can live nearly anywhere, and actually serve a useful role outdoors as nature’s garbage removers (they break down dead material like fallen trees and leaves). Mold spores are almost always in the air, but they’re invisible until they take root in a warm, moist area. Household mold is a sign of excess moisture, as in leaky plumbing, a poorly vented appliance, water damage behind a wall and the aftereffects of flooding. Homes built in damp climates or near a wetland or swampy area are particularly prone to mold outbreaks.
If you have mold in your home, you don’t need anybody to test the air (which can be very expensive and inconclusive); you’ll eventually be able to smell and see it yourself. Most mold species are black or greenish-black, and if there is a lot of mold it gives off a distinctive damp and musty odor. Mold may appear cottony, velvety or fuzzy, or look like grime and dirt, especially on the grout between bathroom tiles. Closets, cabinets, window moldings, shower stalls and curtains, surfaces around air conditioners and even ventilation systems are frequent breeding grounds.
Why worry about mold?
Breathing in mold particles can cause allergic reactions or irritations—coughing, congestion, eye irritation and skin rashes—as well as cause asthma and trigger asthma attacks and chronic sinus infections. Mold can be a serious problem for people with severe lung disorders, asthma or asthma-like conditions. People with compromised immune systems, such as those taking chemotherapy drugs, are at risk for developing very dangerous mold-related lung infections.
Mold also damages home furnishings, fabrics, books and other porous objects. It can harm the structure of your home over time. For these reasons alone, you should take steps to get rid of mold.
Several years ago, frightening stories circulated about so-called “killer mold.” In these reports, outbreaks of Stachybotrys chartarum, also known as Stachybotrys atra, sickened victims with strange maladies, forcing many to flee their homes. Much of the concern focused on mycotoxins—chemicals produced by many species of fungi, including molds. There is no convincing evidence linking mycotoxins to life-threatening symptoms.
However, a few studies suggest that more research is needed on the role that mold and mycotoxins may play in some disorders. Several years ago, the University of Southern California scientists reported that 105 people exposed to different species of household mold experienced symptoms similar to those seen in people exposed to carbon monoxide, diesel exhaust and other common chemical irritants. Symptoms included abnormal changes in memory, thinking and other neurological functions, as well as a reduction in lung capacity. In addition, a study published in the American Journal of Public Health and a review in the European Journal of Internal Medicine in 2007 suggested that mold exposure may be linked to depression, gastrointestinal problems, persistent headaches and other problems.
Hold that mold
The first thing to do is attack the source, which is moisture. If you don’t fix the leaky pipe, hole in the roof or other breach, your mold problem will keep coming back. Consider hiring an experienced contractor or licensed professional to eliminate mold if there’s a lot of it, if it’s in an area that’s hard to reach (such as an attic or crawl space) or if your house smells musty and you can’t determine the cause. Throw out mold-infested furniture, carpeting and other hard-to-clean porous items; replace moldy drywall, insulation, and other affected structural parts. Don’t just paint over moldy drywall or wallpaper, because mold can literally eat paint.
Before you start on a big mold removal project, visit the Environmental Protection Agency (EPA) website, which has excellent cleanup recommendations.
Mold cleanup tips
- Make sure that whoever does the cleanup isn’t sensitive to mold.
- Wear vinyl gloves, goggles without ventilation holes and an N-95 face mask, available in hardware stores. Wear clothes that you can discard or at least wash in hot, soapy water.
- Make sure the area is well ventilated.
- Clean the patch with soap and water. Many authorities, including the Centers for Disease Control and Prevention (CDC), recommend applying diluted bleach (1 to 1.5 cups of bleach per 1 gallon of water) after the soap cleaning. Do not mix the bleach solution with other cleaning products, especially ammonia. Dry the area thoroughly, and throw out used rags, sponges and moldy material.
Mold prevention is the key
- Keep indoor humidity below 50 percent. Use a dehumidifier or air conditioner in areas of your home that are too humid.
- Install exhaust fans in the kitchen and bathrooms.
- Don’t lay carpet in the kitchen or bathrooms; wallpaper may be a bad idea in damp climates.
- If you use a humidifier, clean and disinfect it regularly.
- Remove dead leaves and outside debris, which attract mold.
Originally published December 2010. Updated April 2013.