Molds, mushrooms, mildews, and yeasts are all classified as fungi; a kingdom of organisms different from plants and animals. Bacteria and mold are essentially ubiquitous; in other words, they are present nearly everywhere. The growth of mold is geometric rather than arithmetic; thus, the term amplification is used to describe mold growth when conditions are favorable and visible mold growth forms on surfaces.
The presence of water or excess moisture levels is critical to the amplification of mold since all other elements (i.e., right temperature range, food, mold spores, and areas with limited air velocity and light) are typically present somewhere in an indoor environment. Elevated moisture levels in buildings are typically associated with one of three situations: 1) rain and surface/groundwater entry, 2) elevated humidity levels, causing condensation on building surfaces from both interior and exterior air, and 3) construction moisture present in either the building material or as a result of exposure to the weather prior to completion of the construction.
Provided one reduces or eliminates the source(s) of water/moisture indoors, the amplification of mold is greatly reduced or stopped. However, oftentimes the source of moisture is not immediately apparent. A useful tool for determining the source of interior water moisture (and subsequent mold amplification) is the measurement of indoor air quality (IAQ). The most common and useful IAQ parameters include indoor temperature, carbon monoxide (CO), carbon dioxide (CO2), humidity, and dew point temperature.