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.