The Mycometer is not a mold test. It does not test for mold. It is a test for B-N-acetylhexosaminidase (NAHA), an enzyme produced by a range of organisms that include bacteria, mold, protozoa, and mammalian cells. The Mycometer test is not specific to mold. This is supported by an article in the Journal of Environmental Monitoring:
“NAHA is produced by a range of organisms including bacteria, fungi, protozoa, and mammalian cells and is thus not specific for fungi.” (Ragnar Rylander, Et al, Journal of Environmental Monitoring. DOI: 10.1039/c0em00336k.)
NAHA [the enzyme the Mycometer checks for] is not specific to fungi and can be produced by bacteria, fungi, protozoa, and even mammalian cells therefore is influenced by presence of pollens or pets as well as number of inhabitants.” The Mycometer appears to be more sensitive to detecting filamentous fungi such as Aspergillus. (Reference: INDOOR MOULD TESTING AND BENCHMARKING: A PUBLIC REPORT by the UK Centre for Moisture in Buildings)
None of the studies mention isolating species of mold to see how much enzyme each type of mold present might produce. Yeast, for example, is a common and filamentous fungi. It’s that likely some portion of what is being detected by a Mycometer test is due to yeast. I found no mention of the enzyme in Ainsworth & Bisby’s Dictionary of the Fungi, a text which aims to provide the sum total of accumulated knowledge on systematic mycology.
I have never used the Mycometer for a client because the results cannot be interpreted as some users retailers of the test suggest. The interpretation the criteria provided for the testing are based on studies done to determine “normal” levels of NAHA, not how much mold is present.
There’s no such thing as a normal level of mold growth. There either is or is not mold growth. The Mycometer appears to have one Interpretation Criteria. This results in erroneous interpretations of the data. To make it easier and more useful to interpret results, there should be an interpretation guideline for each type of surface that could possibly be tested. Each type of surface tested must have a baseline area tested. For example, relatively clean bare concrete will have different test results compared to clean wood flooring and clean ceramic tile.
The Mycometer interpretation guidelines that are published for users have not been validated by the EPA. The statement they have been should not be confused with the statement the equipment and process to collect a sample has been validated. The definition of validation is a bit confusing in the context it’s presented.
Now for some positive critique. The Mycometer may have application in determining how clean a surface is. (Just not how mold is present). For example, if a mold remediation company was supposed to have cleaned the floor, using the Mycometer, one should find that testing the surface of a floor inside the work area results in a lower readings than background readings taken outside the work area. The results of the Mycometer readings cannot, however, be stated to say that the readings correlate to levels of mold. It can not be stated there is or is not mold based on a comparison of the readings. One can not use the Mycometer as a mold test, only as a tool in regard to the level of NAHA enzyme on the surface that is tested, an enzyme a lot of living (or dead) life forms produce.
In regard to this application, there are other technologies on the market to assess cleanliness by detecting enzymes, ones better suited. Adenosine triphosphate (ATP) fluorescence testing is used by hospitals and the food industry to verify sanitation. A common brand is Hygiena which makes the device called the Luminometer ATP Bio-Contamination Testing Meter. I have used it in death clean up verification projects to verify cleanliness after remediation was performed.
To give the reader some idea of how variable the results of surface testing can be in regard to cleanliness, and why we don’t use absolute values as baselines to evaluate test results, consider the following data. It contains the test results in a work area that was supposed to have been cleaned, compared to reference samples collected at the house. The baseline is how clean I was able to get surfaces in the reference area using the same tools and cleaning agents the remediation company used. The results are also based on the type of surface. If I had taken only one sample, I might have concluded the work area was still dirty. Averaging the results of five samples I collected, I discovered that the work area was cleaner than I could get the reference area.
If you need assistance knowing what the best type of test to use to find mold in your house is or wonder if it will work, contact us. We can also tell you what the best test is to make sure the mold is gone after you had mold remediation. We can look over test results and tell you if you have accurate information for what you’re trying to achieve.
References:
Rylander, R., 2015. β-N-Acetylhexosaminidase (NAHA) as a Marker of Fungal Cell Biomass – Storage Stability and Relation to β-Glucan. International Journal of Environmental Monitoring and Analysis, 3(4), pp. 205-209.
(24) Terčelj, M., Salobir, B., Harlander, M. & Rylander, R., 2011. Fungal exposure in homes of patients with sarcoidosis – an environmental exposure study. Environmental Health, 10(8), pp. 1-5. 25 Terčelj, M. et al., 2013. Nocturnal asthma and domestic exposure to fungi. Indoor and Built Environment, Volume 22, pp. 876-880.
(27) Rylander, R., Reeslev, M. & Hulander, T., 2010. Airborne enzyme measurements to detect indoor mould exposure. Journal of Environmental Monitoring, Volume 12, pp. 2161-2164.
THE ENVIRONMENTAL TECHNOLOGY VERIFICATION PROGRAM, ETV Verification Statement, TECHNOLOGY NAME: Mycometer®-test).
