Mycometer® air Fungi

For Quantification of Fungi in Air

Test Assays

The tests assays are packed in a box of 20 samples. A box contains all accessories for sampling and analysing 20 samples.

20 Sampling filters
20 Substrates
20 Activators
40 Developers
10 Fluorescent standards
2 Syringes 10 ml
20 Pipette tips (1 ml)

Product Information

Mycometer® air Fungi
  • Onsite results in less than an hour!
  • Verified Technology (USEPA 2011)
  • High data reproducibility

Mycometer® air Fungi is the state-of-the-art test method for onsite quantification of fungal particles in air in less than an hour. The methodology measures the level of fungal particles in terms of viable and most nonviable spores and hyphal fragments. Further, two independent peer reviewed publications have shown that it also measures microparticles from the fungi. The Mycometer® air Fungi methodology quantifies fungal particles in the air by measuring the level of the enzyme, β-N-acetylhexosaminidase (NAHA), from airborne fungal particles captured on a 0,8 µm pore size filter.

The technology is verified by US-EPA (Environmental Protection Agency) and was shown to have a high reproducibility. This high reproducibility is a result of:

  • High level of standardization
  • Objective analysis, not subjective interpretation like e.g. microscopy
  • High and constant collection efficiency
  • Minimal sampling handling

The Mycometer® air Fungi has been chosen as the only methodology for measuring mould in air in the new (2011) Danish Standard DS3033 “Classification of the quality of the indoor climate in residential houses, schools, children´s day-care centres and offices”.

Sampling

25 mm cassette with a 0.8 μ MCE filter (only accepted filter type!)  
Sampling volume of 300L obtained by using a flowrate of 20 LPM
Sampling height at 1,45 m (4.76 feet)

Sampling with Mycometer® air Fungi

Reproducibility of air sampling results can be affected by both; the sample collection process and the analysis. The Mycometer® air Fungi analysis methodology is very reproducible (as documented by USEPA in 2011) so the main source of variability in results is sampling. Experiments have shown that the main reason for variability in air sampling is human or other activity in the room prior to or during sampling. Activity in a space aerosolizes settled mould and other particles. In experiments where passive sampling was applied it was found that, in rooms where there had been no activity for about 12 hours, the level of mould in the air was only around 9 %, sometimes as low as 1% of that found in the same room after the rooms had been occupied for some hours. However, when an aggressive sampling protocol (where a blower was used to uniformly agitate settled particles on surfaces) was used, the level of mould in the air was found to be independent of the level of activity in the room prior to sampling. For most purposes therefore, Mycometer strongly recommends the use of the aggressive sampling protocol developed by Mycometer. In addition to being more representative of the actual presence of fungal particles in the space, the use of the aggressive sampling protocol will significantly decrease the possibility of false negative results.

Safety

Aggressive sampling

For aggressive sampling with the Mycometer® air Fungi method, a MakitaLXT BUB182Z cordless leaf blower is used. It creates a maximum airflow of 43 liters per second. (1.53 ft3/s ), which is close to the range of most household vacuum cleaners. The air speed at 2 meters distance is 3,3 m/sek. It must be used without attachments such as the directional rubber tube or cone.

Sampling in practice

Before taking samples, start by performing a visual examination in accordance with ASTM 7338-10 Standard Guide for Assessment of Fungal Growth in Buildings or other notable guidance documents.
Choose whether a passive or aggressive (agitated) sampling protocol fits your purpose.

Examples of questions a reproducible air sampling method can answer:

  • Are there elevated levels of mould in the air compared to those found in normal non problem buildings or non-complain areas?
  • Are there major differences in the level of air borne mould in different rooms in the building, indicating a mould source? (note that this approach may also help localizing a possible source)
  • Is the final cleaning (removing settled mould particles left from the remediation) successful?
Applications
  • Initial diagnostic assessment
  • Rapid remediation clearance testing
  • Pre/Post HVAC cleaning documentation
  • Healthy Building Assessments
  • Expedite disaster response damage assessment
  • Healthcare ICRA documentation
  • Routine maintenance cleaning confirmation
Documentation and Publications

The Mycometer® air Fungi technology was recently (2011) verified by United States Environmental Protection Agency through the ETV programme. Linearity between enzyme activity measured as fluorescence and the number of spores was well documented(R2 = 0,997). The reproducibility was determined by collecting 8 parallel samples and have them analyzed by two analysts (4 each) using two different analytical instruments. An RPD of 5.3% was found. This is an exceptionally low variability, unprecedented in any other method available for measuring mould in air.

The Mycometer® air Fungi technology has also been documented through peer revieved papers in international journals.

Two new studies have shown that high levels of NAHA enzyme activity (as is measured with the Mycometer-air method) correlate to health issues.

  • High levels of NAHA activity in air samples were found in homes of subjects with sarcoidosis, particularly among those with recurrent disease.
    → Airborne enzyme in homes of patients with sarcoidosis. Terčelj M, Salobir B, Rylander R. Env Health 2011; 10:8-13.
  • A correlation was seen between NAHA activity and Nocturnal Asthma.
    → Nocturnal asthma and domestic exposure to fungi. Terčelj M, Salobir B, Narancsik Z, Kriznar K, Grzetic-Romcevic T, Matos T, Rylander R. Indoor + Built Env 2012; in print.
  • A Swedish study showed that higher levels of NAHA enzyme activity were found in air samples from buildings with mould damage compared to control buildings.
    →  Airborne enzyme measurements to detect indoor mould exposure. Journal of Environmental Monitoring, R. Rylander, M. Reeslev and T. Hulander.010, 12, p.2161–2164.
  • The study showed that the NAHA enzyme activity was found in microfragments from fungi.
    →  NAGase activity in airborne biomass dust and relationship between NAGase concentrations and fungal spores. Aerobiologia, 19, 97 – 105. A.M., Madsen. 2003.
  • The study demonstrated that aggressive sampling improves the predictive value of air samples significantly.
    →  Aggressive Sampling, Improving the Predictive Value Of Air Sampling For Fungal Aerosols. M. Reeslev, M. Miller, JC Nielsen, L Rogers. Proceedings of Indoor Air Conference, ISIAQC. June 2011.
References

Universities and government agencies

The Danish Technical University – DTU (Denmark)
The University of Eastern Finland (Finland)
US Army CHPPM-South, (Korea)
US Army CHPPM South ( Japan)
The Technological Institute of Denmark (Denmark)
US Army- Ft Eustis, Ft Drum, Ft Meade ++ (US)
US Navy – Camp Pendleton, Annapolis ++ (US)
•Instituto de patologia del libro (Italy)
Danish Army Building Services (Denmark)
The Finnish Institute of Occupational Health (Finland)
Defense Intelligence Agency (US)
The Royal Danish Academy of Fine Arts. The School of Conservation (Denmark)
Hochschule für angewandte wissenshaft und Kunst (Germany)
Corps of Engineers (US)
Institut National de Researche et de Securite – INRS (France)
National Security Agency – NSA (US)
CDC/NIOSH (US)
National Institute for Health and Welfare (Finland)
National Institutes of Health -NIH (US)
Institut de recherche Robert-Sauvé en santé et en Sécurité du travail –IRSST (Canada)

Consultants and contractors

EES Group (US)
CETEC (Australia)
National Flood School (UK)
Golder Associates, Inc.(US)
COWI (Denmark)
Regas Group (US)
Goritas building inspection (Denmark)
Building Health Sciences, Inc. (US)
Action Dry Emergency Services (UK)
Industry- and Consultant Services (Norway)
Inuplan (Greenland)
AMiP – Industrial Engineering GmbH (Austria)
Air Purification Specialists (US)
BioFact (Sweden)
Dominion Environmental (US)
ISS (Denmark & Finland)
Docusave (Switzerland)
R&T (Greenland)
Inniluf Tænastan (Faroe islands)
Environ, Inc. (US)
BBJ Environmental Solutions (US)
LBF (Faroe Islands)
Indoor Air Sciences, Inc. (US)
Robson Environmental ( Australia)
ROSE Environmental, LTD ( Trinidad)
ArQi:Mate ( Singapore)
PT Freeport Moran Mining (Indonesia)
Engineering Systems, Inc. (FL, TX) (US)
SSG (Denmark)
National Analytical Labs (US)

Accredited laboratories

ita Laboratorio Oy (Finland)
ISS Proko Oy (Finland)
MetropoliLab Oy (Finland)

FAQ

Should one use an outdoor sample as reference sample?

It is well known that the outdoor level of fungal propagules is extremely variable over time, sometimes changing from minute to minute. There are also huge seasonal variations (in temperate climate) adding to the overall variability. Using spore traps it has been shown that even sampling side-by-side during the same time frame can give results that differ by orders of magnitude. A study presented at a recent AIHce conference showed that under the best weather conditions at least three outdoor samples were needed to have a statistically safe determination of the outdoor level of mould spores. Under the worst weather conditions hundreds of samples were necessary. This means that for practical purposes it is not realistic to be able to establish a statistically safe determination of the outdoor level and therefore not useful as a reference to the indoor air level. In addition, what is immediately present outdoors will not in that same instant be present indoors. The delay of impact from outdoors to indoors is also influenced by presence or absence of a mechanical ventilations system, building envelope tightness, air exchange rate with in the building, air filtration effectiveness and open windows/doors. A more useful control or reference sample would be one collected from an area in the building not suspected to be contaminated or having complaints.

Why do you recommend agressive or agitated air sampling?

Basically to get useful data that can be reproduced and give a much more reliable measure of potential risk of exposure in a room.

An average spherical fungal spore with a diameter of 3 µm settles at an approximate rate of 1 meter per hour in still air. If there has been no activity in a room for many hours prior to air sampling, almost all fungal particles will have settled on surfaces with very little left in the air. Passive sampling in this situation can significantly underestimate what is actually present in a room and which will be aerosolized with normally occurring activity. That is why it is not uncommon to have false negative results in rooms with visual mould growth when using passive sampling.

In a pilot experiment, passive air samples were taken in eight rooms early in the morning before the rooms were occupied and then again late in the afternoon after the rooms had been occupied. The results showed that the airborne fungal levels found in morning sampling were on average only 9% of that found in the afternoon, and in some cases as little as 1%. The same experiment was conducted using aggressive sampling. The results of aggressive sampling found the airborne fungal level early in the morning (where there had been no activity for many hours) on average did not differ from the values obtained in the afternoon where maximum activity had occurred. The significance of this experiment is that it demonstrated that using aggressive sampling eliminated the variability of occupant activity and provides a more reliabily predictive result for the presence of fungal material.

How agressive should an agressive sampling be?

The idea is not to create absolutely the worst case scenario in a room but rather to mimic a high activity level that will sometimes occur, such as if a vacuum cleaner is in use, or a ventilation fan is turned on, or if children are running around. The Makita Blower is used as the standard instrument and has a maximum air flow of 43 l/s, which is close to that of common vacuum cleaners. The protocol prescribes that one blows on surfaces from a distance of approximately 2 meters (air speed 3,3 m/s), and avoid blowing into a radiator, or behind closets, or other places outside the normal cleaning areas. The particles that should be aerosolized, are the ones that are naturally aerosolized, when there is activity, as described above, in a room.

How efficient is filter sampling used in the Mycometer® air Fungi method?

Many independent investigations have demonstrated that membrane filtration (as used in the Mycometer-air method) has very high collection efficiency (around 99%). Spore traps are selective for large to medium sized spores while less than 50% of spores smaller than 2.5µm are collected by most spore traps.
Read more on this subject:

“What does non-viable mean” Indoor Environment Connections, p. 15.
http://www.ieconnections.com/pdfs/newsletter/2012/IEC-10-2012.pdf

“The Screening Sample Scam” p. 3.
http://www.forensic-applications.com/moulds/screening.html

Is air sampling a good tool to evaluate complaint areas for mould?

Yes, when done with aggressive sampling it is the best way if not the only reliable way.

How does Mycometer® air Fungi compare to cultivation method?

Cultivation methods are the only methods that can be used for assessment of viable mould propagules. The limitations are that it doesn’t measure non-viable mould propagules and it only measures a fraction of the viable ones depending on the growth media chosen. In the “Field Guide for the Determination of Biological Contaminants in Environmental Samples” (American Industrial Hygiene Association, 2005) it is stated that in general, the number of propagules are substantially less (1%) than those determined by direct methods (microscopy).

The enzyme activity that is measured in the Mycometer® air Fungi method is present in both viable and non viable fungal propagules. Enzyme activity is found in hyphae and spores in roughly the same amount per biomass unit and has even been found in microfragments (cell wall and other debis from fungi less than 1 µm in diameter).

In short: The Mycometer® air Fungi method gives a better quantitative determination of the level of mould particles in the air, while cultivation is best used for determining species or genera when needed.

Can you find hidden mould growth with Mycometer® air Fungi?

In order to be able to measure a hidden mould source (e.g. in wall cavities or under a floor), fungal particles from the source must physically be transferred into the room were the sample is taken. Furthermore, the level of fungal particles transferred into the room must be significant compared to the normal background level of fungal particles in order to detect it in an air sample. Although this is sometimes the case, often it is not.

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