A type of fungus, molds come in many varieties and exist on different surfaces. Household mold is a sign of excess moisture, as in leaky plumbing, a poorly ventilated 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.
Many mold species are black or greenish-black, and a large amount of mold 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, andsurfaces around air conditioners and ventilation systems are frequent breeding grounds.
For more information on spotting and addressing household mold, see Cleaning Up Household Mold.
This article first appeared in the UC Berkeley 2019 Lung Disorders White Paper.