Understanding Indoor Air Quality

 Among the first steps in evaluating the quality of a building's indoor air is to sample the air and analyze its contents. Here's an overview of the role air-sampling plays in evaluating IAQ.

How to Evaluate a Building for Mold Growth
Check building materials and spaces for visible mold and signs of moisture damage indicating a history of water leaks, high humidity levels, and/or condensation. Any occupant complaints or reported health problems should be noted as well as any musty or moldy odors.

Components of the building's ventilation system should also be inspected. A moisture meter is often very helpful in identifying wet or damp building materials. If mold growth or moisture problems are found, the air pressure differentials between the area of growth and surrounding areas should be determined and potential air pathways from the source should be characterized to determine its impact on the building and its occupants.

Sampling in Building Evaluation
If visible mold is present, then it should be remediated regardless of what species are present and whether samples are taken. In specific instances, such as cases where health concerns are an issue, litigation is involved, or whether the source(s) of contamination is unclear, sampling may be considered as part of building evaluation. In situations where visible mold is present, and there is a need to have the mold identified, sampling is needed. Any sampling must be conducted by professionals experienced with mold issues, and familiar with current guidelines.

If mold is suspected but not visibly detectable after an inspection, then sampling may reveal evidence of mold amplification or reservoirs indoors. If mold is being removed and there is a question about how far the colonization extends, then surface or bulk sampling in combination with moisture readings may be useful. Sampling for airborne mold spores can indicate whether the mix of indoor molds is typical of the outdoor mix or, conversely, atypical or unusual, at least at that time. If samples are taken, regardless of the purpose, there should be a clear question that the sample results should help answer. Sampling without a specific purpose greatly increases the chances of generating useless data. Note that laboratories vary in experience and proficiency; using an accredited lab is recommended.