(for your "peace of mind")
Some of our calls are from people who just need to rule out mold because they are not feeling well. They have been to the doctor; tests have been run but no cause for the problem can be determined.
Nothing that looks like mold is in the house, so where is the mold? - - It could be airborne. And it could be Toxic Mold. Let me add, that if you are sensitive to mold, the mold does not have to be toxic to make you feel bad. There is very little you can do about mold because mold spores are everywhere, but too much mold is not good, even for a healthy person who is not sensitive. So how do you find out? Test the air you breathe. If high mold counts are detected, there is something you can do. The first action is to test it, have samples collected and sent to a laboratory for analyses so that you can make an informed decision based on scientific results.
Spore trap air samples are collected using Zefon "Air-O-Cell" cassettes. The samples are collected using air-sampling pumps set at 15 liters per minute (lpm). Spore trap test results are reported as the number of spores found per cubic meter of air. Calibration of the pump is by a field rotameter, which has been calibrated to a primary standard.
When air samples are collected indoors, at least one air sample is taken outdoors. The outdoors sample establishes a baseline for comparative evaluation of the indoor samples. Because there are no Federal standards for mold spore count levels in residences, schools, or other buildings, the Industry guidelines are derived from NYC (New York City Guidelines) and ACGIH (American Conference of Governmental Industrial Hygienists).
Naturally occurring biological materials such as mold, fungus, and pollen are not regulated by any government agency, and have no regulatory exposure limits. Current acceptable industry practice, as explained in the previous paragraph, considers indoor air quality to be degraded if the mold measured in indoor air is substantially different from the mold measured in outdoor air. If the indoor air samples show elevated levels of mold spores, or inconsistent types of mold, such samples are considered positive for mold. Positive samples indicate the need for additional investigation, supplemental testing or corrective measures. The theory is that any mold in the house comes from outdoors. If there is more indoors, it must come from indoors.
If the results of the indoors are the same or lower than outdoors it is believed that your indoors readings are normal. If the indoors is higher than outdoors, you have elevated readings that are probably being caused because you are growing mold indoors.
Additional papers by George Hatcher.