GLOSSARY OF COMMON MOLDS IN CANADA

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ALTERNARIA

Common Location:

• One of the most common molds is abundant worldwide.
• This genus contains about 40 to 50 different species, only a few of which are commonly found indoors.
• It is common outdoors in soil, dead organic debris, foodstuffs, and textiles. 
• Plant pathogen, found most commonly on weakened plants.
• Indoors, they can be found on a variety of substrates including house dust, in carpets, on damp spots around showers and around window frames and any area where condensation occurs.
• Alternaria conidia are very distinct in characteristic, being ovoid to pear-shaped and forming chains.

Health Risk:

• Commonly recognized.
  
• Type | Allergies (Hay Fever, Asthma).
• Type ||| Hypersensitivity Pneumonitis.
• Because of its abundance and ubiquity, Alternaria is one of the most important fungal allergens.
• Nasal lesions, subcutaneous lesions, nail infections; the majority of infections reported from persons with underlying disease or in those taking immunosuppressive drugs.

Mode of Dissemination:

• Dry spore
• Wind

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ASPERGILLUS

Common Location:

• Aspergillus is so visually similar to Penicillium they are commonly discussed as a group.
• There are approximately 600 different species of Aspergillus.
• These fungi are found in soil, compost piles, plant debris and stored grain, as well as on water-damaged building materials.
• Indoors they are found throughout the home in dust, growing on wallpaper, decaying fabrics, and behind paint.
• They have also been isolated from foods such as nuts, apples, oranges and onions.
  

Health Risk:

• Type | Allergies (Hay Fever, Asthma).
• Type ||| Hypersensitivity Pneumonitis: Humidifier lung, Malt worker's lung, Compost lung, Wood trimmer's disease, Straw hypersensitivity, Farmer's lung, Oat grain hypersensitivity, others.
• Respiratory, invasive, cutaneous, ear and corneal disease.
• Severe, invasive disease is usually associated with immuno-suppressed hosts.
• Fumigatus: Fungus ball and invasive disease.
• Flavus: Nasal sinus lesions, invasive disease.
• Niger: "Swimmer's ear", invasive disease.
• The diseases caused by these species rarely occur in individuals with normally functioning immune systems. Toxin production is dependent on the species or the strain within a species and on the food source.

Mode of Dissemination:

• Dry spore
• Wind

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BOTRYTIS

Common Location:

• Soil stored and transported fruit and vegetables.
  
• Plant pathogen and saprophyte on flowers, leaves, stems, fruit, leaf rot on grapes, strawberries, lettuce, cabbage, onions.
• May be found in conjunction with indoor plants.
• Mostly parasitic on higher plants.
• "Gray-mold" called "Noble rot" on wine grapes.
• Botrytis is used in some types of wine production.

Health Risk:

• Botrytis is known to cause allergies and induce asthma attacks.
• Type | Allergies (Hay Fever, Asthma).
• Type ||| Hypersensitivity Pneumonitis: Winegrower's lung.
• Very rare agent of Keratomycosis.
• No recorded human case of infection.

Mode of Dissemination:

• Wet Spore.
• Wind (When dried out), Water Droplet.

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CHAETOMIUM

Common Location:

• Chaetomium is a common mold worldwide.
• This genus contains about 80-90 different species.
• Soil, seeds, cellulose substrates, dung, woody and straw materials.
• It readily digests cellulose substrates and is frequently isolated from decomposing plant materials, especially woody or straw-like materials.
• In water-damaged buildings, it is frequently found on sheet rock and paper products that have been wet.

Health Risk:

• It is allergenic and occasionally causes systemic or cutaneous phaeohyphomycosis (Infections caused from fungi or yeasts).
• Type | Allergies (Hay Fever, Asthma).
• Uncommon agent of Onychomycosis (Nail Infection).

Mode of Dissemination:

• Spores are formed inside fruiting bodies.
• Spores are forced out an opening and spread by wind, insects and water splash.

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CLADOSPORIUM

Common Location:

• An abundant mold worldwide and normally one of the most abundant spore types present in both indoor and outdoor samples.
• The genus contains around 20-30 different species.
• Soil of many different types, plant litter, plant pathogen, leaf surfaces, old and decayed plants.
• Widespread on many substrates, including textiles, wood, most window sills.
• The enzymes of Cladosporium are especially suited for breaking down Cellulose, Pectin and Lignin, which are major components of plant litter.
• Cladosporium can rapidly invade many different ecological niches, and is therefore considered ubiquitous and sometimes problematic.
• Indoors, this fungus may be encountered in dirty refrigerators, especially in reservoirs where condensation is collected, and on moist window frames.
• Cladosporium often discolors interior paint, paper and textiles stored under humid conditions.

Health Risk:

• Common and important allergen.
• Type | Allergies (Hay Fever, Asthma).
• Type ||| Hypersensitivity Pneumonitis: Hot tub lung, Moldy wall hypersensitivity genereally non-pathogenic.
• Heavy sporulation, easy dispersal, and buoyant spores make it an important fungal airway allergen.
• Togeather with Alternaria, it commonly causes Asthma and Hay Fever in the Western Hemisphere.

Mode of Dissemination:

• Dry Spore (formed in very fragile chains, easily dispersed).
• Wind.

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MUCOR

Common Location:

• Mucor is one of the quicker invading organisms able to contaminate many kinds of stored food products.
• Mucor has worldwide distribution and is often found in hay, stored seeds, horse manure, and house dust, regardless of geographical location.
• It is also frequently found in air samples from indoor environments.
• Accumulated dust in HVAC systems and poorly maintained carpeting may contain high concentrations of Mucor spores.

Health Risk:

• Minor.
• Type | Allergies (Hay Fever, Asthma).
• Type ||| Hypersensitivity Pneumonitis.
• Rare infections in severely debilitated patients.
• Mucor is a rare opportunistic pathogen.

Mode of Dissemination:

• Rain Splash except for M. Plumbeus, which is commonly dry and disseminated by wind.

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STACHYBOTRYS

Common Location:

• This mold is ubiquitous in nature and contains about 15 species.
• It produces wet sticky slimy spores and is found in soil, decaying plant substrates, decomposing cellulose (hay, straw), leaf litter. and seeds.
• Stachybotrys, a dark colored fungi, thrives on water-damaged, cellulose-rich materials such as sheet rock. paper, ceiling tiles, cellulose-containing insulation backing and wallpaper.
• Stachybotrys is slow-growing compared to Penicillium and other common mold genera, and may not compete well in the presence of other fungi.
• However, when water availability is high for long periods on environmental material, Stachybotrys may gradually become the predominating mold, especially on cellulose-containing materials.

Health Risk:

• Not well studied.
• Type | Allergies reported.
• The presence of this fungus in buildings is significant because of the mold's ability to produce extremely toxic (potent) mycotoxins.
• Exposure to these toxins can occur through inhalation, ingestion, or dermal exposure and can include the following symptoms: dermatitis, cough, rhinitis, nose bleeds, a burning sensation in the mouth and nasal passage, cold and flu symptoms, headache, general malaise and fever.

Mode of Dissemination:

• Wet Spore.
• Insects.
• Water Splash.
• Wind when dried out.