Mold Bacteria Consulting Services

Serving Ontario and British Columbia

  • Home
  • About MBS
  • Services
    • Mold Inspection
    • Bacteria Testing
    • Bioburden Testing
    • Legionella Investigation
    • Online Training
  • Equipment/Supplies
  • iBlog
  • Kids’ Corner
    • School Science Fair Projects
    • Bacteria Pictures
    • Fungal Pictures
  • Contact Us
  • Login
You are here: Home / Archives for mycotoxins

Mycotoxins in Indoor Environment

Lyn Gandham

Molds or fungi can be found in at least small amounts almost anywhere due to their release of tiny spores. Spores can be hazardous to human health and potentially cause allergic reactions, fungal infection (mycosis) or release mycotoxins. Mycotoxins are secondary metabolites (toxic chemical products) that can be present with the spores, the mycelium of fungi and even the surface where the fungi grow.

Mold producing possible mycotoxins
Mold producing possible mycotoxins

Not all fungi however produce mycotoxins and, specific environmental conditions are required for these potent compounds to be produced.  Increased mycotoxin biosynthesis within a fungal spore is affected by the following environmental conditions: temperature, water activity and pH. Other factors that affect susceptibility to mycotoxins vary by individual. Such factors include the length and frequency of exposure, the concentration of the mycotoxins, the age, health and sex of the exposed individual, etc.

At a high enough exposure, certain mycotoxins can be harmful or even lethal to both humans and animals. They can enter the body through ingestion, skin exposure and inhalation. Many mycotoxins are allergenic, immunosuppressive, carcinogenic, or can cause kidney toxicity. However, extreme exposure to mycotoxins is rare even in residences with serious mold problems. Further, some mycotoxins can be beneficial to humans; such is the case of penicillin which is used to treat many bacterial infections. The major groups of mycotoxins are: Aflatoxins, Citrinin, Ergot Alkaloids, Fumonisins, Ochratoxin, Patulin, Trichothecenes, and Zearalenone.

Exposure to mycotoxins has a greater likelihood of occurring in areas of the world that do not practice proper food handling and storage of food and, do not have proper government screening and regulation programs. They can appear in the food chain through crop fungal infections or, crops eaten by livestock as feed or directly by humans. Many mycotoxins are also highly resistant to decomposition, digestion, and even heat treatment which allow them to persist in meat and dairy products. Most control methods involve high-performance liquid chromatography (HPLC) techniques to access mycotoxin levels in food. Examples for food products that are currently tested include peanuts and peanut products, tree nuts, corn and corn products, cottonseed, and milk.

Preventative measures such as good agricultural practices and adequate drying of crops post-harvest can be taken to control exposure. Ongoing biotechnology research is also being performed into using bio-control agents, developing crops that have enhanced antifungal genes, and targeting regulatory mycotoxin genes.

Mycotoxins in the indoor air environment:

Mycotoxin detection in indoor air is not well documented and, it is therefore difficult to identify their presence. Current research suggests the concentrations present in a normal home, office or school are too low to trigger an immune response. Examples of molds that are known to have the potential to produce myxotoxins include Alternaria, Aspergillus (many forms), Penicillium, and Stachybotrys.

Of course, the best preventative measure in preventing myxotoxin production in the indoor air is to prevent mould growth. For more information and to find out about our mold testing services, please contact Mold & Bacteria Consulting Laboratories, call our Ontario, Mississauga Office at 905-290-9101 or the British Columbia, Burnaby Office at 604-435-6555.

References:

Bennett JW, M Klich. 2003. Mycotoxins. Clin Microbiol Rev 16(3):497-516.

Jarvis BB, Miller JD. 2005. Mycotoxins as harmful indoor air contaminants. Appl Microbiol Biotechnol 66(4):367-372.

Keller NP, Turner G, Bennett JW. 2005. Fungal secondary metabolism-from biochemistry to genomics. Nat Rev Microbiol 3(12):937-947.

Richard JL. 2007. Some major mycotoxins and their mycotoxicoses-an overview. Int J Food Microbiol 119(1-2):3-10.

Robbins CA, Swenson LJ, Nealley ML, Gots RE, Kelman BJ. 2000. Health effects of mycotoxins in indoor air: a critical review. Appl Occup Environ Hyg 15(10):773-784.

Shephard GS. 2008. Determination of mycotoxins in human foods. Chem Soc Rev 37(11):2468-2477.

Turner NW, Subrahmanyam S, Piletsky SA. 2009. Analytical methods for determination of mycotoxins: a review. Anal Chim Acta 632(2): 168-180.

Filed Under: mycotoxins Tagged With: mycotoxins

Any Input Relative To The Spore Levels Identified?

Jackson Kung'u

Question: My daughter and her room-mate have been housed in a room that has an elevated mold count. The outside mold count on the day of the test was 2,600 spores per cubic meter of air while the count in the dorm in the dorm room was 10,300. The preliminary test identified three different types of mold spores with readings elevated above outdoor readings. These spore types and readings were as follows:

  • Penicillium/Aspergillus:
    • Outdoor count: 907 spores/cubic meter of air
    • Dorm room count: 6,880 spores/cubic meter of air
  • Cladosporium:
    • Outdoor count: 533 spores/cubic meter of air
    • Indoor count: 3,150 spores/cubic meter of air
  • Both girls are experiencing some health issues. My daughter is currently in the hospital with some respiratory issues and an infection of the colon. Can you provide me with any input relative to the spore levels identified? Also, I realize that most problems associated with mold are of the respiratory nature, but I am concerned that the colon infection could also be a result of mold toxins. Is this possible? Any input would be appreciated.

    Answer: Currently there are no acceptable levels of airborne mold spores. However, it’s generally agreed that mold is a health hazard and should not be allowed to grow in occupied indoor environments. The common indoor molds are unlikely to cause infection to health individuals. People with weak immune system (immunocompromised), however, could be infected by opportunistic pathogens such as some species of Aspergillus and Fusarium. As for mycotoxins, it is not known whether the indoor air concentrations of airborne mycotoxins become high enough to cause any significant health effects.

Filed Under: Fungi, Indoor Air Quality, MBL Answers Tagged With: Aspergillus, cladosporium, Fusarium, mycotoxins, penicillium, spores

Mold And Health

Jackson Kung'u

Mold Allergy, Mycotoxins And Mold Infections

How Do Moulds Affect Our Health?

There are three ways in which mold can affect our health. These include allergy, mycotoxin poisoning and infections.

  • Allergenic Reactions

    An allergy is an acquired sensitivity to allergenic particles such as mold spores and pollen. Allergy acquired from a single exposure is specific to one or to closely related species. Multiple exposures may result in multiple sensitivities. Alternaria and Cladosporium are the two most common causes of allergy. Some mold allergies are associated with work environment such as:

    • farmer’s lung (thermophilic actinomycetes, Aspergillus flavus, Aspergillus versicolor, and Eurotium rubrum),
    • cheesewasher’s lung (Penicillium casei),
    • malt-worker’s lung (Aspergillus clavatus, Aspergillus fumigatus),
    • maple-bark stripper’s lung (Cryptostroma corticale),
    • sawmill worker’s lung (Rhizopus rhizopodiformis, Penicillium spp., Aspergillus fumigatus, Trichoderma viride),
    • mushroom picker’s lung (Pleurotus ostreatus, Pholiota nameko, Aspergillus fumigatus, Doratomyces stemonitis).
    •  

  • Mycotoxins

  • Mycotoxins are toxic compounds that some molds produce. These can be introduced into our bodies through inhalation of spores or airborne mycotoxins in dust. However, eating food contaminated with mold is the major route of mycotoxin poisoning. The best known mycotoxins are aflatoxins produced by various species of Aspergillus. Aflatoxins have a history of causing death in animals and humans and also trigger cancer development.

  • Infections

    Infections by common indoor molds is unlikely. However, individuals with weak immune system are at risk of being infected by species of Aspergillus (e.g., Aspergillus fumigatus), Fusarium (e.g., Fusarium solani) and other opportunistic pathogens.

 

References

Hawksworth, D L, Kirk, P M, Sutton, B C & Pegler, D N (1995). Ainsworth and Bisby’s Dictionary of the Fungi. 8th Edition. International Mycological Institute.

Samson, R A., Reenen-Hoekstra, E S., & Frisvad, J C (2004). Introduction to Food-Borne Fungi. 7th Edition. Centraalbureau voor Schimmelcultures, Baarn.

Filed Under: Fungi Tagged With: aflatoxin, allergy, infection, mycotoxins

Chaetomium species as indoor contaminants

Jackson Kung'u

Chaetomium species

Chaetomium globosumChaetomium species are found worldwide in soil, dung, or decaying plants. Most species are prolific producers of the enzyme cellulase that breaks down cellulose. Destruction of paper and other materials containing cellulose (including foods, feeds, paper, textile, bird feathers, seeds and military equipment) by species of this mould is well documented. Due to their strong ability to destroy material, Chaetomium species are often used in testing materials for resistance to mould growth.

Chaetomium is perhaps the third most common indoor fungal contaminant of mouldy damp buildings. It may be found on wet drywall, wall-paper, carpets, window frames, baseboards and plywood. The most widespread and common species is Chaetomium globosum. This species causes many problems of biodeterioration of paper and other cellulose containing material. It is considered a “weed” of mushroom beds, where it inhibits the growth of cultivated mushrooms.

Chaetomium as a contaminant of indoor air

Generally the concentration of airborne Chaetomium spores is very low. This is because the spores (= ascospores) are produced within flask-shaped bodies (= perithecia) and not exposed to air like those of moulds such as Penicillium and Aspergillus. When the spores mature, they are released inside the perithecium and then squeezed out in a column like toothpaste through an opening at the top of the perithecium. The coiled hairs trap the spores such that they are not easily dispersed into the air by wind.Chaetomium globosum spores

The other reason why the concentration of airborne Chaetomium spores is usually low is because the spores are relatively large and hence have relatively high settling rates and therefore do not remain airborne for long. As a result, airborne spore concentration of Chaetomium is usually low even in contaminated buildings. Due to low air concentration, exposure to airborne Chaetomium is insignificant except in situations where the mould has dried out and disturbed.

What does the presence of Chaetomium in a building tell us?
Chaetomium is one of those moulds that require chronic moisture conditions for it to grow. It’s presence is therefore an indication of existing or previous serious moisture problem. A few spores in pre-remediation air samples is an indication of a mould problem in the building. Because of the low airborne concentration, rarely is Chaetomium detected in outdoor samples. Hence any spores detected indoors are highly likely to have a source indoors and not outdoors. One can also sample house dust to determine whether Chaetomium is present or not.

Health Effects

Although Chaetomium species are rarely associated with human infections, there are reports of infections involving individuals with weak immune system. Chaetomium globosum is known to produce 2 toxins in moisture damaged buildings, chaetoglobosins A and C. These toxins have the potential to cause illness to building occupants.

For more information on Chaetomium species,please visit http://www.moldbacteria.com/learnmore/moldlist.html or call 905-290-101.

References

  1. Fogle, Matthew R (2007). Growth and mycotoxin production by Chaetomium globosum. PhD Dissertation, Texas Tech University Health Sciences Center.
  2. Udagawa S, Muroi T, Kurata H, Sekita S, Yoshihira K, Natori S: Chaetomium udagawe: a new producer of sterigmatocystin. Trans Mycol Soc Jap 1979, 20, 475-480.
  3. Domsch KH, Gams W, Anderson T-H: Compendium of Soil Fungi. Academic Press, London 1993.
  4. Arx JA von, Guarro J, Figueras MJ: The Ascomycete Genus Chaetomium. J. Cramer, Berlin 1986.
  5. Barron MA, Sutton DA , Veve R, Guarro J, Rinaldi M, Thompson E, Cagnoni PJ, Moultney K, and Madinger NE, Invasive Mycotic Infections Caused by Chaetomium perlucidum, a New Agent of Cerebral Phaeohyphomycosis. Journal of Clincal Microbiolgy, Nov. 2003, p. 5302–5307 Vol. 41, No. 11
  6. Piecková E: In vitro toxicity of indoor Chaetomium Kunze ex Fr. Ann Agric Environ Med 2003, 10, 9–14.

Filed Under: Fungi Tagged With: cellulase, cellulose, chaetomium, health risks, moisture, mycotoxins

What Are Acceptable Levels Of Mould Spores And What Are The Effects Of Spores On The Human Body?

Jackson Kung'u

After analysing air samples for total spore counts, we often get asked whether there are acceptable levels of mould concentrations in air and what effects mould spores have on human health. Unlike many other indoor pollutants, there are currently no set acceptable levels for mould spores. The scientific community including medical doctors is polarized on the effects of mould on human health. However, it is generally accepted that mould can:

  • Elicit allergic reactions to sensitized (or atopic) individuals and that not all moulds are allergenic
  • Infect humans especially those with weak immune systems
  • Produce toxic metabolites (mycotoxins) that can kill or cause other complications if ingested in food.

While scientific evidence to prove that mould is the cause of some illnesses is lacking, there is enough evidence to support the need to remove mould from occupied environments.

Filed Under: Fungi, Indoor Air Quality Tagged With: health risks, mould allergy, mould spores, mycotoxins

  • 1
  • 2
  • 3
  • Next Page »

What’s New?

  • Indoor Air Quality Testing in Toronto, Ontario
  • Air Quality Testing in Vancouver, BC
  • Mold Testing in Toronto, Ontario
  • Mold Testing in Vancouver, BC
  • Salmonella food poisoning and symptoms
March 2023
S M T W T F S
 1234
567891011
12131415161718
19202122232425
262728293031  
« Jun    

Salmonella food poisoning and symptoms

Salmonella food poisoning has been a growing concern in recent news. It has frequently lead to recalls of beef, salads and organic products and, even peanut butter products. Salmonella food poisoning occurs when one eats raw or undercooked foods such meat, poultry, eggs or egg products. Properly cooked food can get contaminated with Salmonella if […]

Legionella pneumophila – Guidelines for Laboratory Interpretation

Legionella pneumophila is a Gram negative, aerobic bacteria that is characterized as an opportunistic pathogen. It is the cause of Legionnaires’ Disease, a severe form of pneumonia and, it is the cause of Pontiac fever, a non-pneumonic form of L. pneumophila infection. Legionella spp.’s mode of transmission is through aerosols or aspiration of contaminated water. The Public Health […]

The Indoor Mold Is An Early Warning Device

The mold (or mould, in the Queen’s English) has been the victim of a bad press. Mention the word and it conjures up an image of something rotting or in the process of decomposition. And yet, were it not for the mold that inspired the discovery of penicillin millions of lives would have been lost. […]

Copyright © 2023 . Mold & Bacteria Consulting Services (MBS). 1020 Brevik Place, Unit 1A, Mississauga, L4W 4N7. Log in