Environmental illness, sensitivities and allergies are common today. Exposure to mould is associated with an increased prevalence of asthma-related symptoms such as chronic wheezing, irritation symptoms and non-specific symptoms. Living in damp houses is associated with increased rates of disease, and the cause is believed to be exposure to biological contaminants (Institute of Medicine 2000). Occupants in houses that have dampness problems are at greater risk of exposure to mould, dust mites and bacterial endotoxins. Lower socio-economic status has been associated with higher prevalence of respiratory disease (Dales et al. 2002).
What is Mould?
The word “mould” is a term that refers to members of a few dozen filaentous fungi that when, at the right temperature and exposed to moisture, can grow on building materials. Mold growth on building surfaces not only damages these surfaces, but also affects air quality as intact spores, as well as spore and mycelial fragments, are dispersed in the air. These can be inhaled depending on their size and concentration. Exposure to mould is associated with increased rates of respiratory disease.
Good Mould and Bad Mould
There is no type or amount of mould that is acceptable to be present in an indoor space that is normally occupied by human beings nor is there an acceptable exposure limit to mould.
Health Canada, in their Residential Indoor Air Quality Guidelines – Moulds released March 31, 2007, says:
“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.”
What Does It Need To Grow?
There are mould spores in the air almost everywhere; inside you home, office and in the air outside. Mould growth requires three things:
- Temperatures between 10˚C and 30˚C – Ideal living conditions for humans
- 2. Exposure to moisture for a minimum of 24-48 hours – Mould can’t grow without moisture, so keeping your home fry is critical
- Organic food source – most building materials consist of organic materials for mould spores to feed and grow on.
How Do I Manage or Eliminate Mould Growth?
The best way to manage mold growth is to prevent it before it occurs. Prompt attention to condensation, wet basements and wet building materials will eliminate the growth of mould and prevent the increase of other contaminants, such as house dust mites in the built environment. Consult with a professional to can identify sources of basement leaks in your home and provide you with an action plan to permanently repair a leaky basement. Preventive actions are relatively inexpensive compared to the costs associated with mould. The value of prevention is even more obvious when one takes into account health problems that may be avoided.
If mould is already growing in your home or you suspect it is, hire a professional to conduct an investigation to determine if and where mould is present. A typical investigation will include a visual inspection looking signs of mould like discolouration of flooring and wall coverings, a leaky basement, leaking windows, plumbing, ventilation and condensation.
Not all mould is visible and a moisture meter may be required to measure the moisture content in the home’s finishes. FLIR (forward looking infra-red) may be used to look for water behind walls and obstacles. Air samples may also need to be taken to detect airbourne mould spores. Air samples are also good to establish a baseline before remediation and again measure after remediation to determine effectiveness of the remediation.
Once an evaluation is completed, a plan can then be developed to remediate the mould problem in your home. Remediation may include:
- Correction and repair of basement leaks and moisture; and
- Washing surfaces with hot soapy water; and
- Removal of contaminated building materials
A wet basement and the presence of mould can be very stressful; the fear of the unknown, the health risks and damage to your home. If you have a basement leak and/or mould growth in your home, you need to hire professionals to investigate the sources and to design a plan to remediate the mould and correct the water problems.