Mould spores are tiny structures produced by moulds for the purpose of propagation. The term spore is general. There specific terms used for spores depending on how they are produced or the group of fungi producing them. Ascospores for example are spores produced by a group of fungi called Ascomycetes while Basidiospores are spores produced by Basidiomycetes which include the mushrooms.

How would spores affect human health?
Spores are tiny (range between 2-200 micrometers) and therefore are easily inhaled into the lungs. Susceptible individuals react to the protein component of the cell wall of the spores. Some moulds such as Aspergillus fumigatus may also grow in the lungs causing what is referred to as Aspergillosis.

How would you tell if you are inhaling potentially harmful levels of spore concentration?
The way to tell if occupants of a building were inhaling potentially harmful levels of spore concentration is to take air samples. Air may be taken to be analysed by culture methods or by direct microscopic examination. Culture methods may significantly underestimate the total airborne mould concentration in the air because only the viable spores or fragments of the mould can be detected in culture. The spores/fragments may also not be detected if the media used for culturing were not suitable for the types of moulds present in the air. Samples taken for direct microscopic examination (also referred to as non-viable air samples) allow the analyst to count all the spores and fragments regardless of whether the spores were viable or dead. Since susceptible individuals can also react to dead spores, non-viable samples would be the best to give an idea of whether occupants were inhaling potentially hazardous levels of mould spores.

The pictures show spores trapped from highly contaminated indoor air. The first picture shows spores of Chaetomium and Aspergillus/Penicillium. The second photo shows Ulocladium spores and Stachybotrys spores. Chaetomium, Stachybotrys and Ulocladium species are indicators of serious water damage. Spores of these moulds and those of Aspergillus and Penicillium pose inhalation risk.




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Wallemia sebi is one of the so called xerophilic moulds, meaning that it can grow under relatively dry conditions (i.e., low water activity). Wallemia sebi has a world-wide distribution. It is common in indoor environment and has been isolated from jams, dates, bread, cakes, salted beans and fish, bacon, fruits, soil, hay, and textiles. It is also common in agricultural environments where it is suspected to be one of the causes of farmer's lung disease and other human allergies.


Wallemia sebi also produces a mycotoxin called walleminol A. Not much is know about the health effects of this toxin to humans in indoor environment.




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Mould has been there since the time of Adam and Eve. Why has it then become an issue in recent times? People get sick from mould exposure. Were they getting sick before? Post your opions here. Readers would want to hear what you think about indoor mould.


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Scopulariopsis is a large group comprised of a number of species commonly found in soil, decaying wood, and various other plant and animal products. In indoor environment Scopulariopsis is found on damp walls, cellulose board and wallpaper; wood; floor and mattress dust. Species of Scopulariopsis have also been isolated from carpets, hospital floor, swimming pool; wooden food packing, shoes and wood pulp. Scopulariopsis species are sometimes encountered growing on meat in storage.

A number of species of Scopulariopsis are of importance in medical fields, having been implicated in infection of nails. Many species of Scopulariopsis can liberate arsenic gas from substrates containing that element; this may be noticed as a garlic-like odour. In the past, there have been a few serious poisoning incidents due to the growth of Scopulariopsis brevicaulis on dyes used in wallpaper production. There were also suggestions that the infant cot death syndrome (SIDS) may in some cases be caused by Scopulariopsis but this have largely been refuted.

Scopulariopsis brevicaulis is by far the commonest species encountered in indoor environment. It is found growing on all kinds of decomposing organic matter, and flourishes on materials containing a high level of protein, such as meat and ripening cheese. It decomposes cotton, textiles and paper products and causes deterioration of paints. It is also implicated as a human pathogen.

Other common species include: Scopulariopsis acremonium, Scopulariopsis halophilica, and Scopulariopsis fimicola. Scopulariopsis acremonium has been reported as causing the spoilage of free fatty acids in stored barley. Scopulariopsis halophilica is particularly resistant to high concentrations of salt, and causes spoilage of salt fish in various Asian countries. Scopulariopsis fimicola causes the "white plaster mould" of commercial mushroom growing.



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Mold & Bacteria Consulting Laboratories (MBL) Inc. provides laboratory mould testing and identification. We also provide testing for environmental bacteria. Mould testing services include analysis of non-viable air samples (Air-O-Cell, Micro 5, cyclex D, LARO-100, pcm cassettes), viable air samples (RCS, Andersen, etc), direct microscopic and culture analyses of bulk samples (drywall, wallpaper, pieces of carpets, insulation material, dust, wood and other matrices), lift tape and swab or wipe samples. We also assist industrial and occupational hygienists, certified mould inspectors, environmental engineers and other consultants in troubleshooting mould and bacteria problems in industrial, hospitals, offices and residential buildings.

Turnaround time for all culture analyses is 10-14 days. Non-culture analyses takes 2-5 days for regular service and 24 hours for rush service. Please call if you need sampling information or a list of our prices. Download our Chain of Custody (Analysis Request Form.

We serve:

• Certified Mould Remediators (CMR) and Certified Mould Inspectors (CMI)
• Environmental engineering and construction firms
• Industrial and occupational health consulting firms
• Building demolition/restoration contractors
• Homeowners and commercial building managers
• Hospitals/health care facilities, schools, banks, libraries, museums
• Insurance, real estate and legal professionals involved in mould and bacteria issues
• Home inspectors.

Laboratories Services
Mould Testing:

• Air Samples
  Culture (viable) analysis. This includes enumeration of the colony forming units (CFU) and identification of moulds to genus or species. Samples may include RCS, Andersen, LARO-100, or any other media suitable for culture analysis. The report includes a list of recovered moulds and their concentration as colony forming units (CFU), a statistical comparisons of samples where possible and information on the recovered moulds where available.
• Non-viable (total spore count) Analysis. Samples include Air-O-Cell, VersaTrap Cassette, VersaTrap Sampling Cassettes, SKC BioStage, SKC BioCassette, Micro 5, Cyclex D, LARO-100, PCM and other cassettes. This analysis involve spore counting and identification of different categories of mould spores. The report includes spore counts for each category of spores and the grand total spore count for all spores per cubic meter of air. Wherever possible spore counts and categories of spores for all the samples are compared.
• Bulk samples (e.g., drywall material, wallpaper, pieces of carpet, etc). Bulk samples could be analysed by either DME or culturing. A report for DME analysis gives a listing of the observed moulds in rank order. Information of the recovered moulds is also given. Culturing involve identification of recovered moulds to species and listing them in rank order.
• Surface swabs. Swabs could be analysed by direct microscopic examination (DME) or culturing. A DME report for these samples is similar to that of bulk samples. A culture report includes a list of the recovered moulds identified to species level and concentration of these moulds if the analysis involved quantification.
• Lift Tape samples. Tape samples are usually analysed by DME but could also be analysed by culturing. The report produced here is similar to that of DME for bulk samples.
• Dusts (from carpet, upholstery, mattress etc.), Soils and other sediments. These samples are suitable for either culturing without quantification (Direct Plating) or with quantification. They may also be analysed by DME. A report for culturing for quantification lists the recovered moulds and their concentration as CFU per gram of dust or per unit area.
• Sewage and sludge. Suitable for analyses by culturing. Could also be analysed by DME. Reports produced for these samples are similar to those of other samples.

Bacteria Analyses:
The samples discussed above except for lift tape and non-viable air samples could all be analysed for culturable bacteria. Since virtually every sample has some form of bacteria, it is important to have a clear objective for bacteria analysis. Also, some samples are not suitable for bacteria analysis or for some categories of bacteria. MBL analyses samples for the following bacteria:

• Gram Staining and Enumeration of Culturable Bacteria
• Total Coliform / E. coli (Presence/Absence)
• Total Coliform / E. coli (MPN)
• Total Coliform (membrane filter)
• Fecal Coliform (membrane filter)
• Standard Heterotrophic Plate Count
• Legionella Detection.

Consulting Services
We are happy to offer assistance to industrial and occupational hygienists, certified mould inspectors, environmental engineers and other consultants in designing sampling strategies and also determining the most suitable types of samples to take for a given investigation. We also assist field consultants in troubleshooting mould and bacteria problems in industrial, hospitals, offices and residential buildings.

People will normally talk of bread mould. But which mould is the bread. Bread mould could be any of the moulds that commonly occur on bread. Some of the common bread moulds are Rhizopus stolonifer, Chrysonilia sitophila (red bread mould), species of Aspergillus, species of Penicillium, and Monascus ruber. However, any of the indoor moulds can grow on damp bread.

Bread moulds can cause significant losses in bakeries and stores. An outbreak of bread contamination by mould would require careful investigation of the whole bread making and storage processes to identify the source of contamination.



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One of the questions commonly asked by people who have been exposed to mould is whether they should dispose of all their belongings inside the mouldy house including clothes. I will reserve my opinion on this for today. However, I would be interested to learn from other people what they think about disposing of household items including clothes because of mould.


Feel free to comment.


As usual, if you have a question concerning mould, send it to as at My Question.

Myth #1: Mould that come back after treatment with bleach is is mould that is more than one year old.

The Truth: Bleach may not be 100% effective against all moulds. Mould will grow as long as there is moisture, nutrients and suitable temperature for growth. Growth may start from just a few spores or hyphal fragments that escaped bleach or were not killed by bleach. To control mould, one needs to keep the house or building dry. This means the moisture source or causes need to be identified and fixed. The other truth about mould is that there is currently no way of telling how old the mould is and whether it was there one year or two years ago. Spores of some moulds can remain viable on surfaces of building material for several years until they get the right conditions for growth.

Myth #2: Black mould is deadly.

The Truth: All moulds are potentially harmful regardless of their colour. However, not all black moulds are known to cause health problems. Some black moulds that could be of health concern are Aspergillus niger and Stachybotrys chartarum (greenish black). Aspergillus flavus is not black and it is the most well known producer of the potent mycotoxins called aflatoxins. Aspergillus fumigatus is also not black and is one of the biggest concerns in hospitals because it can infect people particularly those with low immunity.

Memnoniella echinata is an indoor mould very similar to Stachybotrys chartarum. The only obvious difference between the two moulds is that Memnoniella echinata produces spores in chains while Stachybotrys chartarum produces its spores in a mass. Memnoniella echinata was previously named Stachybotrys echinata.

Memnoniella echinata has a world-wide distribution and is mainly isolated from soil. Similar to Stachybotrys, it is isolated from cellulose containing materials such as paper, wallpaper, textiles and dead plant material. Sometimes both Memnoniella echinata and Stachybotrys chartarum occur on the same water damaged building material.

Memnoniella echinata produces toxic metabolites similar to those of Stachybotrys chartarum.



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Mold & Bacteria Consulting Laboratories (MBL) Inc. is now offering full-day training seminars on how to recognize indoor mould, how to develop effective sampling strategies and how to interpret laboratory results. If you have been considering attending a similar course, don’t delay to register as we have limited spaces left!

Three Reasons Why You Should Attend

• The course equips you to fully deal with all aspects of indoor mould sampling and interpreting laboratory reports.
• You will have a chance to discuss and get possible solutions of some of the difficult situations or questions you encounter while doing mould investigations.
• You will have an opportunity to learn from others experience.
  
  The course would benefit industrial hygienists, environmental consultants, general contractors, cleaning and restoration contractors, property managers, insurance, financial, and legal professionals who deal with mould issues, and other professionals or anyone interested in increasing their knowledge or developing their decision-making skills related to indoor mould.
  
  For course details, please visit our website at http://www.moldbacteria.com
  
  MBL, Inc. has become one of the premier providers of quality laboratory testing services for mould and bacteria in Canada. MBL offers convenient, rapid turnaround time, competitive pricing and value-added services unavailable at other laboratories, such as free technical information, consulting with the client on the most appropriate test samples and test methods, provide help with the interpretation of results, provide services after working hours if required and provide free unlimited after sales consultation.
  
  Please call (905)290-9101 or visit our website at http://www.moldbacteria.com/ for details of our services.

Stachybotrys chartarum, also known by an old name as Stachybotrys atra, is a cellulose degrading fungus commonly found in soil and on materials rich in cellulose such as hay, straw, cereal grains, plant debris, wood pulp, paper, and cotton. It produces a mass of wet spores sticking together giving the appearance of black pin-heads. The spores (referred to as conidia) are single-celled and ornamented. In indoor environment Stachybotrys thrives on wet cellulose containing material such as drywall and wallpaper. It is thus common in buildings with mechanical or structural defects that result to moisture damage or dampness. It has been isolated from very wet gypsum board/walls and wallpaper; asbestos building substitute; HVAC humidifier water and fans. Although Stachybotrys chartarum mainly survives as a saprophyte (i.e., by feeding on dead organic material), it has also been reported to cause root lesions on soybeans.

Why is Stachybotrys chartarum so feared?
The health effects attributed to Stachybotrys chartarum are controversial. It is generally agreed that Stachybotrys chartarum can potentially cause allergic reactions from inhaled spores and also poses the threat of mycotoxin poisoning. However, there is still a lot of debate as to whether this mould is the sole cause of various illnesses as reported in the literature. One of the recent disputed claims is the idiopathic pulmonary haemorrhage that resulted in deaths of infants in Cleveland, Ohio, USA in 1993-1994. The publicity of this incidence and that of mould related legal cases where Stachybotrys was mentioned has fuelled the public fear for this mould. The mould has been given various names such as “deadly toxic mould” and “deadly black mould”.

What is known about Stachybotrys chartarum and ill-health?
The first reports associating Stachybotrys chartarum with ill-health dates back to the 1930s. Horses and other animals fed with straw and grains in Ukraine and other parts of eastern Europe developed disease symptoms such as irritation of the mouth, throat, and nose; shock; dermal necrosis; a decrease in leukocytes; haemorrhage; nervous disorder; and death. Russian scientists, in 1938, conducted intensive studies and demonstrated that these symptoms were due to mycotoxins produced by Stachybotrys chartarum that had grown on the cellulose rich straw. The disorders were subsequently named stachybotryotoxicosis. There are reports of stachybotryotoxicosis in farm workers who handled contaminated straw. Recent studies have shown spores of Stachybotrys chartarum to contain high concentrations of highly toxic mycotoxins. As mentioned earlier, in 1993-1994, an outbreak of pulmonary haemorrhage in infants in Cleveland, Ohio,USA, was initially attributed to Stachybotrys chartarum. Although studies associating the outbreak with this mould were later reviewed and the reviewers found little evidence to associate the disease with Stachybotrys chartarum, there are still no studies to date to prove or disapprove this association.


Current knowledge about Stachybotrys chartarum

• Stachybotrys chartarum appears to be a species complex.

Recent studies seem to suggest Stachybotrys chartarum consist of closely related individuals in which case it is a species complex. What exactly constitutes Stachybotrys chartarum still remains uncertain. Strains of moulds currently referred to as Stachybotrys chartarum are morphologically and biochemically highly variable. Recently what used to be referred to as Stachybotrys chartarum has been separated into one other distinct species and 2 other strains that were only different from each other by secondary metabolites profiles. The distinct species was named Stachybotrys chlorohalonata. Stachybotrys chartarum and Stachybotrys chlorohalonata require an experienced mycologist to differentiate. The uncertainty of what strains constitutes Stachybotrys chartarum may explain in part the current confusion concerning the health effects attributed to this mould.

• Stachybotrys chartarum produces potent mycotoxins

Stachybotrys chartarum produces a number of potent mycotoxins including trichothecenes Roridin E, Verrucarin J, and Satratoxin H. Trichothecenes are capable of inhibiting the synthesis of DNA, RNA, and protein. These toxins are present on the spore surface, and therefore can be inhaled into the lungs. Studies have also shown that Stachybotrys chartarum trichothecenes can become airborne not only in association with intact spores but also with particles smaller than spores such as fungal fragments. It is, however, not known what level of mycotoxin must be present in the air to affect human health. There is still insufficient evidence supporting a causal relationship between symptoms or illness among building occupants and exposure to mycotoxins.

References
D. -W. Li, C. S. Yang (2005). Taxonomic history and current status of Stachybotrys chartarum and related species. Indoor Air, Volume 15 Issue s9 Page 5 - June 2005

B. Andersen, K. F. Nielsen, U. Thrane, M. Cruse, J. Taylor, and B. B. Jarvis(2003). Stachybotrys chlorohalonata, a new species from water-damaged buildings," Mycologia 95, 1228-1237.

D. M. Kuhn and M. A. Ghannoum (2003). Indoor Mold, Toxigenic Fungi, and Stachybotrys chartarum: Infectious Disease Perspective. Clinical Microbiology Reviews, Jan. 2003, p. 144–172S. Li, G. L. Hartman, B. B. Jarvis, and H. Tak, A (2001). Stachybotrys chartarum Isolate from Soybean." Mycopathologia, 154, 41-49.

Mould not only contaminates our air but also contaminate our food. As the mould grows on food it produces enzymes that break down the food resulting to spoilage. In addition to enzymes, some moulds such as Aspergillus flavus also produce mycotoxins onto the food. Ingestion of mycotoxin-contaminated food is fatal. Hundreds of people in developing countries die every year after consuming grains contaminated with mycotoxins.

Food spoilage due to mould includes off-flavours, mycotoxins contamination, discoloration, and rotting. Spoilage can occur either in the field or in storage. The water activity of the food determines the types of mould spoiling the food.

Moulds commonly found on cereals, nuts and their products.
Aspergillus candidus
Aspergillus flavus
Aspergillus glaucus
Aspergillus niger
Aspergillus ochraceus
Aspergillus parasiticus
Chrysonilia sitophila
Fusarium spp., e.g., Fusarium graminearum
Penicillium citreoviride
Penicillium citrinum
Penicillium expansum
Penicillium islandicum
Penicillium stoloniferum
Penicillium verrucosum
Rhizopus stolonifer


Moulds commonly found on high sugar foods.
Aspergillus glaucus
Penicillium corylophilum
Wallemia sebi


Moulds commonly found on fruits and vegetables.
Alternaria spp
Aspergillus niger
Botrytis cinerea
Cladosporium spp
Fusarium spp
Gloeosporium spp
Penicillium digitatum
Penicillium expansum
Penicillium italicum
Rhizopus stolonifer
Sclerotinia spp


Moulds commonly found on animal products such as meat, eggs, fish and milk
Aspergillus spp, e.g., Aspergillus versicolor
Eurotium spp, e.g. Eurotium herbariorum
Penicillium spp. e.g., Penicillium commune
Scopulariopsis spp.



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Proliferation of indoor mould and bacteria in dwelling places could lead to ill-health of the occupants. Indoor microbial growth and dampness has been associated with a number of respiratory problems including:

• Respiratory symptoms such as coughing and wheezing.
• Respiratory infections such as aspergillosis.
• Allergic diseases, including allergic asthma and bronchitis.
• Non-inflammatory, unspecific symptoms, e.g., eye and skin irritation, fatigue, headache, nausea, and vomiting.

The best way to control microbial growth in a building is to ensure the building is well maintained and any water leaks are repaired promptly.

Once mould has grown in a building, the solution to the problem is to have the water source identified and repaired and the mould removed. This can be expensive especially if the work is to be performed by professionals.

To avoid expensive mould investigation and removal, the homeowners and property managers should:

• Continuously monitor for any water leaks and have them repaired promptly.
• Continuously monitor for mould growth so as to detect it before it spreads.
  

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Fusarium species exist as plant pathogens or saprophytes on plant debris and in soil. Plant parasitic Fusarium cause wilting of many plants including crops such tomatoes, bananas, sweet potatoes, pigeon peas, and pears. Some species of Fusarium are commonly isolated from seeds especially those of cereals. Species of Fusarium also produce a number of different mycotoxins which include trichothecenes (T-2 toxin, HT-2 toxin, deoxynivalenol (DON) and nivalenol), zearalenone and fumonisins. The Fusarium species are probably the most prevalent toxin-producing fungi of the northern temperate regions and are commonly found on cereals grown in the temperate regions of America, Europe and Asia. These toxins have been shown to cause a variety of toxic effects in both experimental animals and livestock and are also suspected to cause toxicity in humans.

In indoor environment Fusarium species are commonly found under very wet conditions. They are commonly isolated from carpet and mattress dust; damp walls, wallpaper; polyester polyurethane foam; humidifier pans and other areas where stagnant water occurs in HVAC systems. Some species cause keratitis in man, and infects eyes and finger nails. Fusarium species are also an inhalation hazard.


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Moulds have a protein and polysaccharide components that make them potentially allergenic to sensitized individuals. Due to their small size, mould spores are able to penetrate deep into the respiratory tract where they can elicit allergic reactions. There are 2 types of respiratory allergy, the type I allergy (immediate hay-fever or asthma) and the type III (delayed farmer’s lung). Type I allergy occurs only in atopic (allergic) individuals.

Type I allergy may be caused by plant pathogens such as Tilletia caries, Fulvia fulva, and Leptosphaeria nodorum. Saprophytic moulds such as Cladosporium herbarum and Alternaria spp occurring in indoor environment or from rotting vegetation can also cause type 1 allergy. Mouldy straw, hay and decaying leaves are important sources of allergenic moulds such as Aspergillus fumigatus, Aspergillus flavus, Aspergillus niger, and Penicillium spp.

There are occupational pulmonary and epidermal allergies. The former occur in the cheese industry (Penicillium roquefortii), the breweries (Aspergillus clavatus), mushroom farms (Doratomyces sp) and compositing sites (various moulds). An example of epidermal or skin allergies is the cane harvesters allergy caused by Arthrinium sp.


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