What to Do if Your House Is a Breeding Ground for Mold

The air circulating inside your home may be full of contaminants that pose a serious threat to your respiratory health. And overly pungent cleaning products are just part of the problem. Pet hair and dander, mold, carbon soot and dust mites all can present danger throughout your indoor environment.

Mold is the number one source of contamination and lowered air quality in homes, according to Jeffrey May, M.A., a certified indoor air quality professional with a master’s in organic chemistry from Harvard University. May is the principal scientist at May Indoor Air Investigations in Tyngsborough, MA. "I have been out there in the trenches," he says. "I’ve taken over 25,000 air samples, and mold is a very significant health risk."

Raymond G. Slavin, M.D., professor of internal medicine and microbiology and past director of the division of allergy and immunology at St. Louis University School of Medicine, agrees: "Mold can be a source of true allergy, which can account for rhinitis or asthma. And there is very good evidence that mold-sensitive children have more severe asthma and respiratory problems throughout their lives."

The World of Mold

As May points out in his book Jeff May’s Healthy Home Tips: A Workbook for Detecting, Diagnosing and Eliminating Pesky Pests, Stinky Stenches, Musty Mold, and Other Aggravating Home Problems, there are two categories of fungi: macrofungi (mushrooms) and microfungi (mold and mildew; in common usage, there is no difference). Microfungi produce microscopic spores along the surface of fungal growth, and these spores are what can be detrimental to respiratory health. One microfungus in particular, Aspergillus—a genus that includes about 200 different species of mold—is common and can be quite toxic. When the tiny spores of Aspergillus mold become airborne, they sometimes cause severe allergic and asthmatic reactions. "It may be that the immune system is primed to react to some molds, or types of fungi, rather than others," speculates May. "And I think that the immune system is primed to recognize Aspergillus mold."

Becoming Sensitized

Inside the lung, Aspergillus "secretes enzymes that digest tissue," says May. "Cell receptors called protease-activated receptors (PARs) are made to recognize these enzymes from mold and bacteria. The PARs system produces an inflammatory response." That inflammation is associated with asthma and allergic reactions.

"When people get sensitized to mold," says Dr. Slavin, "they produce allergic antibodies. These are the same antibodies that cause allergies to ragweed, cats and peanuts. Once you have developed IgE antibodies in response to an antigen—Aspergillus or some other kind of mold—there is no getting rid of them."

"The best example of this is a condition called bronchopulmonary aspergillosis, where mold can actually get into the lung and grow," says Dr. Slavin. "Once you have an allergy, you need to reduce exposure. Then you need to see an allergist and take medications."

Eradicating Mold

If the mold is a result of moisture seeping in through the foundation, "the first line of defense is to keep water away from the outside of your home," says May. "People should get an umbrella and go outside during the rain and see how the gutters are working. It’s so simple, yet few people do it. One night during a rainstorm, I walked around my neighborhood, and only one gutter system besides my own was working properly."

May points out that mold often grows in one particular area: "About eight out of ten times, it’s where the downspout is. An easy daytime check is to take a garden hose and turn it on next to the downspout, then head to the basement to see if there is moisture coming through the wall."

In order to keep rainwater away from the foundation, try installing a pipe either under or attached to the drainpipe, May suggests. This pipe can lie on the surface of the ground and be attached with an "L" joint, "but the best solution is to attach a four-inch PVC pipe to the downspout and dig a trench, maybe eight inches deep and ten or twenty feet long, or as far out from the house as necessary, to a downslope or landscape furrow—and that can be the end of water in your basement forever. It’s inexpensive and just that simple." You can often stop a leak, but eradicating mold requires professional help.

Once the source of dampness is dried up, the next step is getting rid of the mold that remains. This, May says, is not something you should usually do yourself. "You need the right equipment to contain the mold and protect yourself from it, and you want to make sure the mold doesn’t get spread throughout your home." To find the right contractor for the job, May suggests that you contact the Indoor Air Quality Association. "They have a list of contractors who are members. When they show up, you want to be sure they mention the word containment. That’s the most essential procedure. Containment means the area where the mold is being removed is separated from the rest of the house using plastic sheeting."

Publication Review By: the Editorial Staff at HealthCommunities.com

Published: 24 Aug 2010

Last Modified: 22 Jan 2015