In This Issue
- Common Building Moulds
- Hazard Classes of Moulds
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Breaking News: Round Robin
Mold & Bacteria Consulting Laboratories (MBL) Inc. is participating in a Round Robin testing of proficiency spore trap samples with 3 other laboratories, 2 in the USA and 1 in Canada. The objective is to ensure results from these labs are of the highest quality possible. |
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Quality Assurance
Mold & Bacteria Consulting Laboratories (MBL) Inc. is proficient in the Environmental Microbiology Proficiency Analytical Testing (EMPAT) Program. EMPAT is a performance evaluation program, sponsored by AIHA, for environmental microbiology laboratories specializing in analysis for microorganisms commonly detected in air, fluids and bulk samples collected from schools, offices, hospitals, industrial, agricultural, and other work environments.
Click here to read more about the program. |
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How to... Tips
To save money, learn which samples to take and the analytical methods to use at Collecting and Sending Samples to a Laboratory.
Interpreting laboratory results is not always easy. Read how to at How to Interpret Laboratory Results. |
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Out! This is your newsletter. Let us know which topics to include in the next issue. If we don't have the information we will research on it.
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Industry News
Home Dampness and Molds, Parental Atopy, and Asthma in Childhood: a Six-year Population-based Cohort Study. The results of this study were consistent with the hypothesis that heredity is a strong determinant of childhood asthma and also provided further evidence that exposure to moulds increases the risk of developing asthma in children. Read the whole paper at Environ Health Perspect 113:357-361 (2005). |
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What's
Ahead
In the next Issue...Quantitative Laboratory Results. What do they tell us? Don't miss this one! |
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Us Please feel
free to forward this issue to friends and associates. Anyone can subscribe for free:
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To contact us:
Dr. Jackson Kung'u
Mold & Bacteria Consulting Laboratories (MBL) Inc.
jkungu@moldbacteria.com
1020 Brevik Place, Unit 1A
Mississauga, ON L4W 4N7.
Phone: (905)290-9101
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Common Building Moulds and Their Hazard Classes |
Damp materials with a water
activity value equal to or greater than 0.90 are usually
colonized by strains of Aspergillus fumigatus,
Trichoderma spp., Exophiala spp.,
Stachybotrys spp., Phialophora spp.,
Fusarium spp., Ulocladium spp., and yeasts
such as Rhodotorula spp. Materials with a water
activity value ranging from 0.90 - 0.85 are colonized by
Aspergillus versicolor while those with water
activity values of 0.85 or slightly less are colonized
by Aspergillus versicolor, Eurotium spp.,
Wallemia spp., and Penicillium spp., such
as Penicillium chrysogenum and Penicillium
aurantiogriseum.
Hazard Classes of Moulds
In some countries indoor moulds have been grouped
into 3 hazard classes based on associated health risk.
These classes are similar to risk groups assigned to
microorganisms handled in laboratory environments.
- Hazard Class A: includes fungi or their
metabolic products that are highly hazardous to
health. These fungi or metabolites should not be
present in occupied dwellings. Presence of these fungi
in occupied building requires immediate
attention.
- Hazard class B: includes those fungi which
may cause allergic reactions to occupants if present
indoors over a long period.
- Hazard Class C: includes fungi not known to
be a hazard to health. Growth of these fungi indoors,
however, may cause economic damage and therefore
should not be allowed.
See which hazard class each of the common building moulds belong to at Common Indoor Moulds.
Is Sampling and Testing for Mould Necessary?
Yes. Building occupants need assurances that they were not exposed to moulds that may cause health problems. Some of the objectives for laboratory testing are:
- To determine which moulds are growing in the building and hence the level of protection required for both the occupants and remediation staff.
- To determine the presence/absence of airborne spores, their composition and concentrations in situations where occupants complain of mould related ill health but with no obvious visible mould growth.
- To determine if spores from visible growth sources had become airborne.
- To detect and quantify certain mould species.
- To determine the effectiveness of remediation work.
To read how to distinguish mould growth, click March Newsletter, Issue #3.
References
Gravesen S, Nielsen PA, Iversen R, Nielsen KF. (1999). Microfungal Contamination of Damp Buildings--Examples of Risk Constructions and Risk Materials. Environmental Health Perspectives, Supplements Volume 107, Suppl 3:505-8.
Sedlbauer, K., (2002): Prediction of mould fungus formation on the surface of and inside building components. Doctoral Dissertation, Fraunhofer Institute for Building Physics.
ABOUT THE AUTHOR:
Dr. Jackson Kung’u is a Microbiologist who has specialised in the field of mycology (the study of moulds and yeasts). He is a member of the Mycological Society of America. He graduated from the University of Kent at Canterbury, UK, with a Masters degree in Fungal Technology and a PhD in Microbiology. He has published several research papers in international scientific journals. Jackson has analysed thousands of mould samples from across Canada and is currently the Principal Microbiologist for Mold & Bacteria Consulting Laboratories (MBL) Inc. MBL provides laboratory mould and bacteria testing and identification services to environmental consultants, indoor air quality professionals, institutions and homeowners across Canada. Get more information about indoor mould and bacteria at http://www.moldbacteria.com.
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