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You are here: Home / Archives for spore

Do I Vacate The Property Until The Mold Is Remediated?

Jackson Kung'u

Question: If penicillium/aspergillus-like spore counts are 4,700 and outdoor is 100, does this warrant vacating the property until the mold is remediated? I believe the mold has been there for close to 2 years and I have symptoms such as chronic yeast infections of armpits and rash on face, open sores on arms and severe chemical sensitivities.

Answer: Currently there is no set safe or unsafe number for airborne fungal spores. You have indicated that you have symptoms such as chronic yeast infections of armpits and rash on face, open sores on arms and severe chemical sensitivities. In that case you may consider to vacate the place during remediation.

Filed Under: MBL Answers Tagged With: airborne fungal spores, Aspergillus, remediation, spore, yeast infection

Are These Levels of Spores Considered Hazardous?

Jackson Kung'u

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.

Filed Under: MBL Answers Tagged With: Aspergillus, chaetomium, cladosporium, mould, penicillium.crawlspace, spore, spores

Mold In The House And Air Quality

Jackson Kung'u

Question: My question regards mold in the house and air quality. I have a tenant complaining about the air quality in a house I own. It’s a very clean 15 year old home and the basement carpet is 4 years old and in excellent condition. There are no damp conditions and the climate is very dry here. I think this is a frivolous complaint giving him reason to vacate and break our lease agreement. There are no noticeable smells or signs of mold in the house or moisture anywhere in the house. In September clean water entered the basement from a broken sprinkler that was just next to the window. Within 3 hours we had thoroughly shop vaccumed about 3 gallons out of the carpet and pad, sprayed the concrete, pad and carpet with Pinesol. We then separated the layers with 2X2’s and paint cans, set up fans and opened the windows. We relaid the dry pad and carpet on the 4th day. There was no mildew stains and the musty carpet smell was minimal and had dissipated completely within 2 weeks. My tenant’s wife has Asthma and allergies. They had the house inspected and 7,553 Aspergillus/penicillium spores per cubic meter of air were shown in the basement on the report and 2071 on the main floor. Are these spores a health risk? Does this mean there is excessive mold in the house? Is this an uncommon condition for a basement? Do you think this condition was caused by the wet carpet from 4 months ago? Since there is no musty smell would these spores be dormant? Should I replace the carpet? Is the source of these spores likely to be from somewhere else in the house? Should I hire another test from a different company? I appreciate your input.

Thanks.

Answer: Thank you for your question(s). It’s common to have mold in the house. Currently there are no permissible levels for airborne mold spores. The large inter-individual variability in human response to exposure to different mold species and strains makes it difficult to set exposure limits. Therefore, 7,553 aspergillus/penicillium spores per cubic meter of air could be a problem to some people and not to others. Health risks depend on exposure and, for asthma symptoms, on allergic sensitization.

You have mentioned that your tenant’s wife has a history of asthma and allergies. This suggests that she could be at risk. Growth of mold in the house is due to presence of moisture. It’s possible that there were some areas that didn’t get completely dry within 48 hours and hence the growth of species of Aspergillus and/or Penicillium. These molds do not require a lot of moisture for growth. You may consider hiring a qualified professional with experience in mold investigation to come and try to determine the source of those spores and also determine whether there are still some moisture issues that you’re not aware of. They should also be able to advise you whether it’s necessary to replace the carpet or not.

Spores of Aspergillus and Penicillium species could remain dormant for many years. It’s known that even dead spores can cause allergic reactions to those who are sensitive to mold. As for your tenant, I would suggest you let them go. While the tenant’s asthma and allergies may have nothing to do with mold in the house, it’s perhaps better to let them go for their peace of mind and as a show of good will on your part.

I hope you found my comments useful. Please feel free to contact me again if you have any other questions.

Dr. Jackson Kung’u.

Filed Under: MBL Answers Tagged With: air quality, allergy, asthma, basement, mould, spore, spores

What’s New?

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May 2025
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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. […]

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