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Canadian Residential Indoor Air Quality Guideline For Moulds

Whenever mould testing is performed people want to know whether the levels of mould detected are harmful or not. While there is enough evidence to suggest exposure to indoor mould result in an increased prevalence of asthma-related symptoms such as chronic wheezing, irritation symptoms, and non-specific symptoms it has proved difficult to set exposure limits for mould. Health Canada has issued a residential indoor air quality guideline for moulds as quoted below:

“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. “

Any visible mould should be removed safely. There are mould guidelines that outline safe procedures for mould removal. Most of these guidelines are available on the internet.

If you are a homeowner or an occupant of a house and you see visible mould growth, you may want to send samples to a laboratory for testing. The lab report would tell you the types of mould species growing in the house and whether they are known to be of health concern. But remember, regardless of the types of moulds present, the mould has to be cleaned.

How Dangerous Is Mould In Your Basement?

Basements tend to be damp thus encouraging mould growth. Some of the common moulds in basements include Aspergillus versicolor, Penicillium spp, Aspergillus fumigatus and Fusarium spp. However, the types of moulds present in a basement would depend on how damp the basement is. For example, under extremely damp conditions the dominating moulds would be those that require high levels of moisture for growth such as Ulocladium, Stachybotrys, Fusarium, and Aspergillus fumigatus. Under relatively dry conditions, the dominating types of moulds would be those that can grow at low moisture levels such as Aspergillus versicolor, Penicillium chrysogenum, Eurotium species and Wallemia sebi.

Are These Moulds Dangerous?
Allergenic and toxic hazards of common indoor moulds are dependent on the quantity of mould present and the health status of individual person. However, regardless of the amount of mould present or the health status of occupants, mould should never be allowed to grow indoors.

How To Recognize Mould Growth

Mould growth can be recognized by appearance and texture (a magnifying glass can help). Generally, mould growth could appear as fluffy, velvety or hairy spots or patches of various colours.

Mould growth may not be visible at the early stages of growth or if it is of the same colour as the surface on which it is growing. If a material susceptible to mould growth has been damp for a few days, chances are that there is some mould growing on it even if it is not visible.

If not sure whether what you are looking at is mould or not or you want to know what species (type) of mould is growing in a building, you can send samples to a lab for testing. Click Mould Testing Lab for details.

If interested on how you can recognize mould in a buildings or how you can interpret laboratory results, click Mold Training for details.

What Are the Early Signs of Mould Growth?

A concerned homeowner wanted to know the early signs of mould growth. At the initial stages of growth, mould may not be visible to the unaided eye. However, prevailing indoor conditions are a good indicator of potential mould growth. If the building has excess moisture due to roof or pipe leaks, flooding or condensation one would expect visible mould growth to appear on the damp surfaces at some point.

Musty or earthy odour could suggest there was some hidden microbial growth behind and underneath surfaces, such as carpets, wallpaper, cabinets, and walls. Visible mould growth may appear hairy or as slimy coloured patches that increase in size as the mould grows. It is difficult to tell the type of mould growing on a surface on the basis of colour. It is erroneously thought that visible black mould growth is Stachybotrys. There are many other indoor moulds that appear black or grey. The best way to know the type of mould growing indoors is to send a sample to a reputable laboratory for testing. For details on how one can take and send a sample to a laboratory click Mould in Your House.

Mould Training And Certification

The mould inspection and remediation industry has created a demand for mould training at various levels. Some organizations provide mould awareness seminars to property managers, renovation and general contractors, lawyers dealing with mould issues and insurance adjusters among others. The mould awareness seminars are not meant to turn an individual to professional mould inspectors. The seminars usually cover topics such as the causes of mould growth, mould growth control and mould remediation.

Short courses leading to some sort of certification are also out there. Whereas short mould training courses may be adequate to equip one with basic mould investigation and sample collection, a longer mould training or a strong background in microbiology is required for one to be able to deal with the intricacies of mould investigation and testing.

If looking for a comprehensive short mould training course, visit http://www.moldbacteria.com/training.html. This course is meant for:

  • Industrial hygienists,
  • Environmental consultants,
  • Home Inspectors,
  • General contractors,
  • Cleaning and restoration contractors,
  • Property managers,
  • Insurance adjusters, financial, and legal professionals who deal with mould issues.

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. […]