Getting answers There are three test methods, typically used together as a suite, to determine whether mold accumulation and exposures are occurring. One way is to sample the vacuumed dust from surfaces. The sample is then either microscopically scanned looking for mold spores, or is cultured in appropriate growth media to determine its mold population. Comparing the ratio of outdoor leaf-decomposing molds to those known to grow in building materials indicates if the composition of the dust is normal or skewed, indicating potential exposure and health issues. A second, complementary method is to conduct air sampling, injecting the particles in indoor air onto a petri dish with appropriate growth media, in order to determine what types of mold are growing.
Interpretation is similar to the settled dust sample.
The types of mold are compared with what should normally be present. In essence, the settled dust technique paints a picture over time of what typical exposures may have existed over the last few months, while the direct air sampling method gives a snapshot of the exposure levels at a moment in time. Nobody likes false negatives, especially professionals with errors and omissions insurance, given that unknown and potentially harmful exposures could result to people. The third test method is to conduct a thorough physical inspection of the building, focusing on the areas behind walls where moisture may be present. Thorough visual examination for moisture and mold, the quantity of mold present within the building can be estimated.