There are hundreds of thousands of types of molds. All are fungi, which means they are many-celled organisms that reproduce by sending tiny seeds called spores into the air. Molds need four things to grow: food, air, the right temperature and water. Although fungi grow naturally "outdoors", molds are very common in buildings and homes and will grow anywhere indoors where there is sufficient moisture.

A fungus problem usually starts with an injury or harsh chemicals under the nail plate at the free edge, creating a pocket in which the fungus can develop. It grows through the nail, turning black/green when reaching the top. Filing will not kill it, This type of problem must be looked at by a doctor. Yeast is perhaps the most common. The free edge pulls away from the plate, and if not checked can continue to the matrix area. Mold can happen anywhere moisture collects.

Anything can mold as long as there is moisture or a food source. Carpet, including those made of natural fibers such as wool, that is kept clean and dry shouldn’t have a mold problem.

A fungus is a microorganism derived from the plant family; it is a relative of the mushroom. Fungal infections differ from bacterial and viral infections that can affect the nails in that fungal infections are chronic, not tender, slow-growing, and localized. Bacterial and viral infections, on the other hand, are acute, tender, grow rapidly, and are blood borne, meaning they can affect more than one part of the body. A true fungal infection of the nail is called onychomycosis.

When molds are disturbed, they release spores into the air. You can be exposed by breathing air containing these mold spores. You can also be exposed through touching moldy items, eating moldy food or accidental hand to mouth contact.

You don't need to sample for mold because in most cases you can see or smell mold. Even a clean, dry house will have some mold spores, but not enough to cause health problems. If you smell mold it may be hidden behind wallpaper, in the walls or ceiling or under the carpet. If you suspect you have hidden mold be very careful when you investigate, protect yourself from exposure in the same manner as you would for a clean-up. See chart below:

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. Links to external resources are provided as a public service and do not imply endorsement by the Washington State Department of Health.