As explained in a previous blog, it is not necessarily the amount of surficial mold growth that is a potential issue in a home, office or other indoor environment; it is the quantity and type(s) of airborne mold.  Airborne mold is what you are exposed to in your body via the conduits of your lungs and skin. So what do established health and environmental agencies state about how much mold is “safe”?

Oddly, there are currently no agreed upon levels of airborne mold that signify contamination and no health-based guidelines exist. While some researchers suggest the levels should be less than 33% of outdoor levels, others suggest that up to twice the outdoor air concentration is acceptable.  So how does one interpret the results of indoor air testing?

An experienced mold inspector will take into account a number of factors when interpreting test results. One factor that must be considered at all times is the amount of intrusion of outdoor air. For example, a home with open windows and doors may have spore concentrations that are up to 95% of outdoor spore levels, while a large office building with central HVAC and a low air exchange may have only 5% of outdoor levels. This is why it is recommended to seal the space (leave doors and windows closed) as much as possible for 24 hours prior to sampling.  Another important factor is the types of spores found in the sampling. In homes or buildings where there is mold contamination, one or two spore types may dominate the air samples and often these types are not present in the outdoor air or present in low concentrations. The third factor to consider is the physical symptoms of the person(s) that are regularly exposed to the air in that space.

Mold Exposure

Many types of mold spores (and possibly all) are allergenic and capable of causing allergic responses in susceptible individuals. Some fungi are also human pathogens. Some human pathogens cause mild or annoying conditions, such as ringworm or athlete’s foot, while other human pathogens can cause debilitating diseases. Until more data becomes available on dose-response relationships to specific fungi, investigators must rely on their knowledge, experience and site specifics to interpret sampling data.

If you have any additional questions please feel free to contact Dan at 727.321.9296