Mold Bacteria Consulting Services

Serving Ontario and British Columbia

You are here: Home / Archives for spores

Sampling For Airborne Fungal Spores

Reasons for Conducting Air Sampling For Fungal Spores

Air sampling pump
Air sampling

Sampling for airborne fungal spores may be conducted for a number of reasons including assessing the air quality, detection of pathogenic organisms, epidemiological surveys and predictions, detection of mycotoxin producing fungi, or detection and measurement of exposure to allergenic fungi and actinomycetes. Before sampling for airborne fungal spores it’s important to have a clear objective and the data that would meet that objective. Some of these objectives require counting and identification of the airborne fungal particulates. A well calibrated pump is therefore required. The method of sampling, the equipment and the media are determined by the data required. For example if one is interested in species identification, then they would collect culturable air samples using an Andersen or RCS sampler.

Methods for Sampling for Airborne Fungal Spores

Culturable Air Samples

If the air was sampled by impaction onto a growth media, then the samples are first incubated at suitable temperature followed by counting and identification of resulting colonies (if any). A number of factors may affect the reliability of the colony counts data. These include the suitability of the agar media used for sampling, colony density, and presence of fast growing isolates. Some agar media are highly selective and therefore would not suitable when the objective was to determine the diversity of fungal species in the air. If the colony density is very high, then counting becomes difficult. In the presence of fast growing isolates, slow growing isolates are masked and hence difficult to count.

Non-culturable Air Samples

The second method of air sampling is where the air is impacted on inert medium, usually a filter membrane or adhesive-coated slide. The collection medium is then analyzed by transmitted light microscopy (popularly known as direct microscopic examination), typically at 600–1000 × magnification. A number of different collection devices may be used for spore trap sampling of which the most common are slit or circular impactors such as the Air-O-Cell®, Allergenco D, Micro 5, Cyclex D and other similar cassettes. Mixed cellulose ester membrane (MCEM) filters are also occasionally used.

Choose Your Spore Trap Analytical Labs Wisely

Identification of airborne fungal spores to species can only be accomplished by an experienced mycologist. Similarly, spore trap analysis requires considerable skill and experience on the part of the analyst to identify spores accurately, and to differentiate them from other airborne particulate. In most cases identification of airborne fungal spores by direct microscopic examination is limited to genus. In some cases identification of spores to specific genus is difficult. A good spore trap analyst requires several years of experience. A recent multi-laboratory comparative study of spore trap analyses found that only 75% of commercial accredited labs could consistently identify correctly Cladosporium spores and only 50% could identify Aspergillus/Penicillium-like spores consistently. The level of experience required for species identification or spore trap analysis cannot be attained in a short time, and it cannot easily be acquired by individuals lacking advanced training in mycology or plant pathology.

Mold & Bacteria Consulting Laboratories is accredited by CALA to the Internationally recognized ISO/IEC 17025:2005. 

Is This An Adequate Solution To The Mold Problem?

Question: I work in a 100 year old wooden building that suffered from flood conditions last fall. The basement is a dirt floor and has very high spore counts and visible mold. The upstairs suffered from visible mold and high mold counts. The remedial work that has taken place is to put a polythene vapour barrier between the basement and the upstairs. Is this an adequate solution to the problem.

Thank you.

Answer: The solution you’ve described sounds inadequate. Any material with visible mold should have been cleaned or replaced if it could not be easily cleaned. The cause of flooding should also have been investigated and corrected. Since there are no mold remediation standards most mold remediators and restoration contractors follow existing mold guidelines. All the guidelines outline procedures to be followed to clean up the mold. Below are some Mold Guidelines and other useful resources.

  • Guidance for Clinicians on the Recognition and
    Management of Health Effects Related to Mold Exposure and
    Moisture Indoors 

     

  • Fungal Contamination in Public Buildings:
    Health Effects and Investigation Methods 

    Health Canada – This document is a revision of an
    earlier version published by Health Canada and the
    Federal-Provincial Advisory Committee on Environmental and
    Occupational Health (CEOH) in 1995.

  • Mould Guidelines for the Canadian
    Construction Industry 

    Canadian Construction Association (CCA) – Recent
    rerelease of CCA 82. Hard copies can also be purchased from
    your local construction associations.

  • Environmental Abatement Council of Ontario (EACO) Mould Abatement Guidelines.
  • Guidelines on Assessment and Remediation of Mold in Indoor EnvironmentsNew York City Department of Health and Mental Hygiene

Any Input Relative To The Spore Levels Identified?

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.

What Are The Health Issues We Face?

Question: We rent a 2 bedroom basement apartment in North Vancouver, BC. It does rain a lot, and a wet puddle forms in my son’s bedroom. This house is 60 years plus, but we just found mould growing under my son’s bed, black and brown mushroom looking, and we have only lived here for 10 months. We have a small dog, what are the health issues we face? I am 56 and I have a heart disease. My son is 24 and has breathing problems. We have a small 7 year old bichon frise that sleeps a lot.

Answer: There are a number of health effects associated with exposure to indoor moulds. Exposure to indoor mould mainly occurs through inhalation of airborne spores. Therefore, people exposed to indoor mould are likely to experience respiratory problems. Health effects, however, depends on the amount of mould present, individual’s sensitivity to mould and the type of mould. In an indoor environment hundreds of different kinds of mould are able to grow wherever there is moisture and an organic substrate (food source). Mould can grow on building and other materials, including: the paper on gypsum wallboard (drywall); ceiling tiles; wood products; paint; wallpaper; carpeting; some furnishings; books/papers; clothes; and other fabrics. Mould can also grow on moist, dirty surfaces such as concrete, fiberglass insulation, and ceramic tiles.

I would suggest you ask the landlord to hire a professional who could assess the extent of mould contamination, the cause and then recommend how to correct the moisture problem and get rid of the mould.

Are These Levels of Spores Considered Hazardous?

Question: The crawlspace in our condo has the following readings for spores/m3 : Aspergillus/Penicillium type-16000; Chaetomium- 67; Cladosporium- 227. Are these levels spores considered hazardous? It is going to cost a very high amount to have vents, sensors and spores removed to correct the situation and there is no guarantee. Please give me your comments on this.

Answer: There are no published standards for acceptable exposures to indoor mold spores. And there is no agreement among the scientific community on the exact levels of airborne indoor mold spores which are responsible for the onset of disease, nor is there adequate information on dose-effect relationship.

This is what Health Canada advises:

Health Canada considers that mould growth in residential buildings may pose a health hazard. Health risks depend on exposure and, for asthma symptoms, on allergic sensitization. However, the large number of mould species and strains growing in buildings and the large inter-individual variability in human response to mould exposure preclude the derivation of exposure limits. Therefore, Health Canada recommends:

  • to control humidity and diligently repair any water damage in residences to prevent mould growth; and
  • to clean thoroughly any visible or concealed mould growing in residential buildings.

These recommendations apply regardless of the mould species found to be growing in the building.

Further, in the absence of exposure limits, results from tests for the presence of fungi in air cannot be used to assess risks to the health of building occupants.”

For more information regarding mold spores please call us at 905-290-9101 in Ontario or 604-435-6555 in British Columbia.

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. […]