Current Environment:

What is mold exactly, and where is it coming from?

Mold is a natural part of the environment and can be found almost anywhere. It produces tiny spores to reproduce, which waft through the indoor and outdoor air continually. When excessive moisture or water accumulates indoors, mold growth will often occur, particularly if the moisture problem remains.

There is no practical way to eliminate all mold and mold spores from the environment; the way to control indoor mold growth is to control moisture.

How can I clean up mold?

It is important to dry water-damaged areas and items within 24 to 48 hours to prevent mold growth. If mold is a problem in your home, clean up the mold with water and detergent and get rid of excess water or moisture.

How can I control moisture?

Water in your home can come from many sources, often entering your home by leaking or by seeping through basement floors. The colder the temperature, the less moisture the air can hold. If water is entering the house from the outside, your options range from simple landscaping to excavation and waterproofing. Some guidelines to follow are:

  • Replace absorbent materials such as ceiling tiles.
  • Install household maintenance equipment such as exhaust fans, dehumidifiers, and vents to help simple moisture problems.
  • Fix the source of any water problem or leak.
  • Reduce indoor humidity (to between 30 and 60 percent) to decrease mold growth by venting bathrooms, dryers, and other moisture-generating sources to the outside.
  • Clean and dry any damp materials and furnishings.
  • Prevent condensation: Reduce the potential for condensation on cold surfaces by adding insulation.
  • In areas where there is a perpetual moisture problem, do not install carpeting.

Testing for mold

Testing can be expensive. If you believe that you have a problem with mold, you can call your local Board of Health for names of industrial technicians that will test for mold in your area.

To detect mold growth, inspect your house for fungal growth, water damage, and earthy odors, sampling surfaces and the air. Test only for viable colonies in CFUs (colony forming units), and compare indoor and outdoor test results.

Test results need to be interpreted very carefully. Remember, testing can be biased toward fungi with larger spores, leaving room for error. Only certain molds in high quantities trigger concern, not all molds. For example, cladosporidium and alternaria are of little concern. However, mold growth with more than 500 CFUs can be dangerous. Stachybotrus chartarum and pathogenic and toxigenic fungi such as cryptococcus, aspergillus, and penicillium (certain species) are of concern.

What are the possible health effects?

  • hypersensitiity reactions: asthma, allergic rhinitis, and hypersensitivity pneumonitis
  • airway and conjunctival irritations
  • acute toxicity syndromes
  • infections: wound infections, thrush, systemic infections, and skin infections
  • nonspecific symptoms, such as eye irritation, coughing (both productive and non-productive), sore throat, headache, and difficulty concentrating

If I have been exposed, what kind of medical tests should I get?

Medical testing can be done by your practitioner, including:

  • RAST testing for mold allergens
  • skin testing for common allergens
  • serum antibody testing for IgG levels and response to antigens
  • pulmonary function tests for respiratory status


More information is available at the U.S. Environmental Protection Agency (EPA) website at