Got Mold? Frequently Asked Questions About Mold

What are molds?
With more than 100,000 species in the world, it is no wonder molds can be found everywhere. Neither animal or plant, molds are microscopic organisms that produce enzymes to digest organic matter and spores to reproduce. These organisms are part of the fungi kingdom, a realm shared with mushrooms, yeast, and mildews. In nature, mold plays a key role in the decomposition of leaves, wood, and other plant debris. Without mold, we would find ourselves wading neck-deep in dead plant matter. And we wouldn't have great foods and medicines, such as cheese and penicillin. However, problems arise when mold starts digesting organic materials we don't want them to, like our homes.

How do molds grow in my home?
Once mold spores settle in your home, they need moisture to begin growing and digesting whatever they are growing on. There are molds that can grow on wood, ceiling tiles, wallpaper, paints, carpet, sheet rock, and insulation. When excess moisture or water builds up in your home from say, a leaky roof, high humidity, or flooding, conditions are often ideal for molds. Longstanding moisture or high humidity conditions and mold growth go together. Realistically, there is no way to rid all mold and mold spores from your home; the way to control mold growth is to control moisture.

How can I be exposed to mold?
When molds are disturbed, their spores may be released into the air. You then can be exposed to the spores through the air you breath. Also, if you directly handle moldy materials, you can be exposed to mold and mold spores through contact with your skin.  Eating moldy foods or hand-to-mouth contact after handling moldy materials is yet another way you may be exposed.

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How can molds affect my health?
Generally, the majority of common molds are not a concern to someone who is healthy.  However if you have allergies or asthma, you may be sensitive to molds. You may experience skin rash, running nose, eye irritation, cough, congestion, and aggravation of asthma. Also if you have an immune suppression or underlying lung disease, you may be at increased risk for infections from molds.

When necessary, some resourceful molds produce toxins in defense against other molds and bacteria called mycotoxins. Depending on exposure level, these mycotoxins may cause toxic effects in people, also. Fatigue, nausea, headaches, and respiratory and eye irritation are some symptoms that may be experienced from exposure to mycotoxins. If you or your family members have health problems that you suspect are caused by exposure to mold, you should consult with your physician.

How do I know if I have a mold problem?
You may have seen white thread-like growths or clusters of small black specks along your damp bathroom or basement walls, or smelled a "musty" odor. Seeing and smelling mold is a good indication that you have a mold problem. However, you cannot always rely upon your senses to locate molds. Hidden mold can be growing behind wall coverings or ceiling tiles. 

Common places to find mold are in areas where water has damaged building materials and furnishings perhaps from flooding or plumbing leaks. Mold can also be found growing along walls where warm moist air condenses on cooler wall surfaces, such as inside cold exterior walls, behind dressers, headboards, and in closets where articles are stored against walls. Rooms with both high water usage and humidity, such as kitchens, bathrooms, laundry rooms, and basements are often havens for mold. If you notice mold or know of water damaged areas in your home, it is time to take action to control its growth.

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How can I control mold growth in my home?
Fix any moisture problems in your home:

• Stop all water leaks first. Repair leaking roofs and plumbing fixtures. Move water away from concrete slabs and basement walls.

• Increase air circulation within your home, especially along the inside of exterior walls, and ventilate with fresh air from outside. Provide warm air to all areas of the home. Move large objects away from the inside of exterior walls just a few inches to provide good air circulation.

• Install and use exhaust fans in bathrooms, kitchens, and laundry rooms.

• Ventilate and insulate attic and crawl spaces. Cover earth floors in crawl spaces with heavy plastic.

• Clean and dry water damaged carpets, clothing, bedding, upholstered furniture within 24 to 48 hours, or consider removing and replacing damaged furnishings.

• Vacuum and clean your home regularly.

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How do I clean up mold?
The time you are most likely to stir up spores and be exposed is the very time you are trying to clean up your mold problem. That's when you need to be the most careful. First, try to determine the extent of the mold infestation. If the area is small and well defined, clean up can be done by you, as long as you are free of any health symptoms or allergies. However, if the mold problem is extensive, such as between the walls or under the floors, you should leave clean up to a professional.

Clean all furnishings exposed to mold.

Are landlords required to inform tenants about mold?

Yes!  In 2005, the Washington State legislature approved Engrossed Senate Bill (ESB) 5049 (See especially Section 2.12) that requires landlords to notify their tenants about mold. For more information on these requirements, see the DOH Web page on this requirement for landlords and the timing of notification.

Who can I contact for more information?
Should you need additional information on mold, please contact Tim Hardin of the Washington State Department of Health at (360) 236-3363 or tim.hardin@doh.wa.gov.