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What Causes Hydrophilic Fungi?

Fungi are classified according to how much water they require to grow. Hydrophilic fungi need the most water, and include such species as Stachybotrys chartarum and Chaetomium globosum. Waiting fungal spores germinate when the conditions are right, as long as there's an ample supply of water, air and food. Water-damaged homes are a common breeding ground for this type of fungi. The Centers for Disease Control suggests homeowners use caution when removing fungi, as some species have been associated with respiratory illness.

  1. A Source of Water

    • Fungal spores are everywhere, waiting for the right conditions in which to grow. The spores become airborne and attach themselves to all surfaces inside a home and out. When there is standing water present, such as after a flood or near a broken pipe, the spores germinate. Stachybotrys fungi can also grow when the relative humidity is above 90 percent. Hydrophilic fungal spores are often hidden inside walls and grow readily when introduced to moisture from roof or wall leaks. The optimal germination temperature varies by species, but is generally from 70 to 90 degrees Fahrenheit. A supply of oxygen is also required.

    Something to Eat

    • Once the fungal spores have germinated, a food source is required to sustain the colony. While the fungi can digest the same foods as humans, they just as easily feed off the cellulose in building materials. Hydrophilic fungi have a low nitrogen requirement and are able to digest wet wallpaper, wet hay, ceiling tiles, insulation materials and carpet. Fungi feed most readily on materials derived from plants, but are able to utilize other materials with less organic content as long as there's a consistent water supply.

    Occurrence and Rate of Growth

    • Hydrophilic fungi grow slower than other species, usually spreading up to two weeks after the onset of optimal conditions. Some fungi, such as Aspergillus, can propagate in one day. Once established, however, hydrophilic fungi often become the dominant species in an environment. The CDC does not cite the rate of occurrence in homes, but does say that colonies of hydrophilic fungi such as Stachybotrys chartarum are not rare in water-damaged buildings.

    Health Concerns and Removal

    • Fungal spores aggravate allergies in some people. A few species of hydrophilic fungi also contain mycotoxins known to cause respiratory illness. According to a February 2008 research article from the National Institute for Occupational Safety and Health, studies found an association between hydrophilic fungi in floor and chair dust and respiratory illnesses. The CDC advises treating any fungal growth with caution. Most colonies are removed from non-porous surfaces with a solution of 1 cup of bleach and 1 gallon of water. Porous surfaces often require removal and replacement. Contact a professional if the growth is significant. After cleaning and removal, keep the area dry by using a dehumidifier and fixing leaks.

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