Indoor Air Quality

The quality of the air we breathe inside a building can be affected by a wide range of physical, chemical, and biological properties. The Indoor Air Quality (IAQ) for a room or building is a result of the interactions between all these influences. Helpful information about indoor air quality is available from the Meharry EHS Department and on the EPA website.

Health Effects

Molds are usually not a problem indoors, unless mold spores land on a wet or damp spot and begin growing. Molds have the potential to cause health problems. Molds produce allergens (substances that can cause allergic reactions) and irritants. Inhaling or touching mold or mold spores may cause allergic reactions in sensitive individuals. Allergic responses include hay fever-type symptoms, such as sneezing, runny nose, red eyes, and skin rash.


Allergic reactions to mold are common. They can be immediate or delayed. Molds can also cause asthma attacks in people with asthma who are allergic to mold. In addition, mold exposure can irritate the eyes, skin, nose, throat, and lungs of both mold-allergic and non-allergic people. Symptoms other than the allergic and irritant types are not commonly reported as a result of inhaling mold. Research on mold and health effects is ongoing.


The above does not describe all potential health effects related to mold exposure.


Mold Testing

In most cases, if visible mold growth is present, sampling is unnecessary. Sampling the air for mold spores is usually for the purpose of either documenting the effectiveness of mold remediation or answering questions about the presence of mold that is not visibly obvious. Surface sampling also may be useful to determine if an area has been adequately cleaned or remediated. Since no EPA or other federal limits have been set for mold or mold spores, sampling cannot be used to check a building’s compliance with federal mold standards. Sampling for mold should be conducted by professionals who have specific experience in designing mold sampling protocols, sampling methods, and interpreting results. The MMC EHS Department has the ability to thoroughly evaluate and test for mold concerns.


Outdoor air always contains some level of mold spores. Indoor air should have less mold in the air than the outdoor air since HVAC systems filter and dehumidify the air. Indoor air is expected to have similar types of mold as outdoor air due to open doors and windows and other holes in the building envelope, as well as inefficiencies of HVAC filtering. However, if mold is growing in an indoor environment due to water damage or some other undesirable condition, the indoor mold types and/or quantities will be higher than the outdoor samples.


EPA 10 Things you should know about mold

  1. Potential health effects and symptoms associated with mold exposures include allergic reactions, asthma and other respiratory complaints.
  2. There is no practical way to eliminate all mold and mold spores in the indoor environment; the way to control indoor mold growth is to control moisture.
  3. If mold is a problem in your home or school, you must clean up the mold and eliminate sources of moisture.
  4. Fix the source of the water problem or leak to prevent mold growth.
  5. Reduce indoor humidity (to 30-60%) to decrease mold growth by:
    • Venting bathrooms, dryers, and other moisture-generating sources to the outside
    • Using air conditioners and de-humidifiers
    • Increasing ventilation
    • Using exhaust fans whenever cooking, dishwashing, and cleaning
  1. Clean and dry any damp or wet building materials and furnishings within 24-48 hours to prevent mold growth.
  2. Clean mold off hard surfaces with water and detergent, and dry completely. Absorbent materials such as ceiling tiles, that are moldy, may need to be replaced.
  3. Prevent condensation: Reduce the potential for condensation on cold surfaces (i.e., windows, piping, exterior walls, roof, or floors) by adding insulation.
  4. In areas where there is a perpetual moisture problem, do not install carpeting (i.e., by drinking fountains, by classroom sinks, or on concrete floors with leaks or frequent condensation).
  5. Molds can be found almost anywhere; they can grow on virtually any substance, providing moisture is present. There are molds that can grow on wood, paper, carpet, and foods.

Contact EHS

Dept. of Environmental Health & Safety
1005 Dr. D. B. Todd, Jr., Blvd.
Nashville, Tennessee 37208
Telephone: 615.327.6642