The Mycometer is a used by some mold inspectors to determine the level of mold or bacteria on surfaces or in air. I don’t recommend or use the Mycometer to test for mold. The following are a few reasons why:
The Mycometer is not a mold test. The Mycometer does not test for mold. The Mycometer test is not specific to mold (1). The Mycometer tests for B-N-acetylhexosaminidase (NAHA), an enzyme produced by a range of organisms that include bacteria, mold, protozoa, and mammalian cells.
INDOOR MOULD TESTING AND BENCHMARKING: A PUBLIC REPORT. UK Centre for Moisture in Buildings, states: “NAHA [the enzyme the Mycometer checks for] is not specific to fungi [mold] (23) and can be produced by bacteria, fungi, protozoa(24), and even mammalian cells therefore is influenced by presence of pollens or pets as well as number of inhabitants (27).”The paper mentions the Mycometer appears to be more sensitive to detecting filamentous fungi such as Aspergillus. The authors do not give an explanation for how or why. None of the studies I reviewed mention isolating species of mold to see how much enzyme each type of mold produces. Yeast is a filamentous fungi. It’s likely some portion of what is detected by the Mycometer is due to yeast.
In regard to testing preformed by mold inspectors using the Mycometer, the interpretation guidelines have not been validated by the EPA. To say they have been, as some do, is misinformation. The following link: (THE ENVIRONMENTAL TECHNOLOGY VERIFICATION PROGRAM, ETV Verification Statement, TECHNOLOGY NAME: Mycometer®-test). https://archive.epa.gov/nrmrl/archive-etv/web/pdf/p100dzkz.pdf.) does into detail. The EPA has verified the procedure in which samples are to be collected- not whether the test results are valid. Mycometer test reports that contain the logo for the USEPA Environmental Verification Program are misinformation.
I was introduced to the Mycometer when I saw a presentation at an Indoor Air Quality Association (IAQA) conference.·While I was intrigued, I’ve never used the Mycometer for a client, as the results cannot be interpreted as suggested. The interpretation criteria are based on studies for what is deemed “normal” levels of NAHA, not how much mold is present. With respect to the Danish Building Research Institute, the Mycometer might have an application in determining how clean a surface is.
For example, if a mold remediation company was to have cleaned the floor, then using the Mycometer, one should find that testing the surface of the floor inside the containment area results in lower readings than background readings taken outside the containment area. It cannot, however, be stated that the readings correlate to levels of mold. It cannot be stated there is or is not mold based on a comparison of readings. One cannot use the Mycometer as a mold test, rathe as a tool in regard to the level of NAHA enzyme on the surfaces tested.
There are other technologies on the market that assess cleanliness by detecting enzymes. Adenosine triphosphate (ATP) fluorescence testing is used by hospitals and the food industry to verify sanitation. A common brand of devices is made Hygiena, the Luminometer ATP Bio-Contamination Testing Meter. I have used it for a death clean up verification.
To give the reader some idea of how variable surfaces can be in regard to cleanliness, and why we don’t use absolute values as baselines, consider the following data. It contains the results in a work area that was supposed to have been cleaned, compared to reference samples. The baseline is how clean I was able to get the surfaces in the reference area using the same tools and cleaning agents the remediation company used, and based on the type of surface. If I had taken one sample, I might have concluded that the work area was dirty. Averaging the results of five samples, it was found that the work area was cleaner than I could get the reference area to be.
The Mycometer appears to have only one Interpretation Criteria for surfaces. Each type of surface tested must have a baseline area tested. “Clean” bare concrete may have different results compared clean wood flooring and clean ceramic tile. None of these results can tell you if there is or is not actual mold growth present.
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REFERENCES
(1) 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.” (“Airborne enzyme measurements to detect indoor mould exposure.” Ragnar Rylander, Et al, Journal of Environmental Monitoring. DOI: 10.1039/c0em00336k.)
(23) 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.