Seven Facts About Household Mold

Below are seven facts about household mold.

1. Mold is a fungus.

   Like all fungi, it thrives in damp, dark places. Its ecological role is the decomposition of organic matter. Mold grows in many colors, from black to bright. Mildew, often found with mold, is a separate species of fungus, and is usually whitish or grey in color.

2. Mold can be toxic.

   Mold reproduces by releasing spores, which germinate in dank places. Some spores carry mycotoxins, or toxic compounds. Medical research has linked mycotoxins with sickness in humans and animals. Symptoms range from mild allergic reactions, to bowel and respiratory disease.
   
   Not all mold produces mycotoxins, but several toxic species of mold can exist in a home. These include black mold (Stachybotrys chartarum) and Aspergillus. The common brown mold in the bathroom is usually Cladosporium, a less toxic variety.

3. Mold is used in bread, beer, and medicine.

   Penicillium is the greenish-blue mold on food such as oranges, or the mystery meat in the fridge. As its name suggests, it's used to make penicillin. Yeast helps make bread and beer. Production of the Japanese liquor, sake, uses a species of Aspergillus.

4. That musty smell comes from mold digesting its food.

   Mold eats anything organic. Among other things, it consumes wood, clothing, drywall, insulation, plants and household dust.
   
   It eats by dissolving its food with digestive enzymes. Then, it inserts hyphae, or microscopic roots, into the food solution, and absorbs the nutrients. As it digests, mold excretes gasses, which have a rank, musty odor.

5. Mold can affect animals.

   In 2005, dozens of dogs died when mold infested a shipment of corn used for dog food. Farm animals have also suffered the effects of toxic mold in feed or hay. Two cats died during routine dental exams, after the New Orleans flood. Examiners found high concentrations of mycotoxins from mold in their bodies.

6. Bleach will kill mold, but not prevent it.

   Acidic cleaners like bleach and muriatic acid will kill mold on surfaces, but often the problem goes deeper. Once a few spots appear on a wall, mold has probably overrun the other side. Spot cleaning will not destroy the mold growing in walls or floors.

7. Mold needs humidity to live.

   Like all living things, mold needs food, oxygen and water to survive. Mold grows wherever moisture leaks, stands or condenses. It's often found behind pictures and curtains. Good air circulation and a dehumidifier will combat mold growth. The Centers for Disease Control and Prevention recommends a household humidity level of not more than 45%.

Mold has its uses, but is not a welcome houseguest. The more we know about mold, the more we can prevent its spread in the home and workplace.