Molds are part of the natural environment. Molds are fungi that can be found anywhere – inside or outside – throughout the year. About 1,000 species of mold can be found in the United States, with more than 100,000 known species worldwide.  Outdoors, molds play an important role in nature by breaking down organic matter such as toppled trees, fallen leaves, and dead animals. Indoors, mold growth should be avoided. Molds can grow on virtually any substance, as long as moisture or water, oxygen, and an organic source are present. Molds reproduce by creating tiny spores (viable seeds) that usually cannot be seen without magnification. Mold spores continually float through the indoor and outdoor air.

Molds are usually not a problem unless mold spores land on a damp spot and begin growing. There are molds that grow on wood, paper, carpet, foods and insulation, while other molds feast on the everyday dust and dirt that gather in the moist regions of a building.  When excessive moisture or water accumulates indoors, mold growth often will occur, particularly if the moisture problem remains uncorrected. While it is impossible to eliminate all molds and mold spores, controlling moisture can control indoor mold growth.

How to Recognize Mold

  • Sight – Usually appear as colored, woolly mats.
  • Smell – Often produce a foul, musty, earthy smell.

Potential Health Effects of Mold Exposure

  • Runny nose, Eye irritation, Cough/congestion, Sneezing, Skin rash, Aggravation of asthma

People at Greatest Risk of Health Effects

  • Individuals with: a weakened immune system, allergies, sinusitis, or asthma and other lung diseases.

If You Think There is Mold in Your Workplace

The best way to control mold is to control moisture, so any sources of water, moisture or leaks must be fixed.  Notify your building manager or enter a work order if clean up or repairs are needed.  If you have questions about mold affecting your health, contact Environmental and Occupational Health.


Environmental and Occupational Health
Phone: 608-890-1992