Gravity plates measure viable mold spores that are actively airborne during the sampling period. The results can give you a snapshot of indoor air conditions at the time the test was taken.

However, there are limitations to be aware of:

• They do not detect dead spores or fragments, which may still trigger symptoms.
• They can underrepresent certain mold species that don’t grow well in culture or don’t easily settle from the air.
• They provide a brief window of data—only what was present during the one-hour exposure.

This means a test that shows little or no growth does not necessarily mean the environment is free of mold. Likewise, a few colonies of common outdoor molds are not always a cause for alarm. These results must be interpreted in the context of building history, occupant symptoms, and additional observations.