Specimen Collection

Indoor Air

[Proximate outdoor air is also tested for the control sample 1.] For reliable results, the equipment used includes a controlled volume air pump, which draws air through an Air-O-Cell™ cassette (spore trap) at 15 liters per minute (lpm). Pump controls are adjusted using a field rotameter that has been calibrated to a primary standard. Spore trap test results are reported as the number of spores found per cubic meter of air. Spore trap air samples are not cultured, and test results include counts of both living and dead* spores (as well as pollen). This test is referred to as a “snapshot” of the air at the exact time of sampling, and is used to determine the mold genera that are present.

In special cases where the species of mold needs to be identified, air is sampled with the intent of culturing live spores. A spore collection plate that contains a growth medium is placed in a viable impactor (microbial particle sampler) and the attached air-sampling pump is adjusted to 28.3 liters per minute. Air is directed, through precise apertures, onto the growth medium, and one hour of natural spore settling time is replicated in five minutes. Cultured sample results indicate the number of viable spores in the air at the time of sampling.[* It is important to note that allergic reactions can come from dead spores and living spores alike. In addition, the toxins that fungal spores produce remain toxic after the spore itself has died.]