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The Air Quality Blog

Welcome to my Blog. This is where I`ll discuss interesting experiences and unique situations related to indoor air quality. Topics to include my experiences with mould remediation, asbestos abatement, air quality testing and my mechanical engineering background. If you have questions relevant to any of the topics, please feel free to email them to me; I`ll include them here as well to share the help. See our posts on the EHealth forum under Northern_aqs.

Thanks for your interest!

Topics & Date

Mould and the Wild West (Ontario) - February 2011

When do you need an indoor air quality professional? - March 2011

What can I do if I'm living with black mould? - March 23, 2011

Do it yourself mould testing: should I give in to temptation? - April 20, 2011

Mould Behind Walls? - May 29, 2011

Balancing Energy Efficiency and Indoor Air Quality - June12 , 2011





Mould and the Wild West (Ontario)

It may come as some surprise to readers from Ontario, that there are no current regulations (legal standards) for the amount of airborne mould spores that are permissable indoors within Ontario. It may come as a shock to learn that there are no formal regulations to dictate the safety standards or methodology required to perform a mould remediation in Ontario.
The logic behind the absence of regulation regarding airborne mould spores makes sense in one regard because of the vast variation in the ambient spore load in different locations throughout the province. Mould is a naturally occurring organism and is present everywhere the conditions required for its survival and reproduction are present. In areas with little natural vegetation (decomposing plant matter is the most common source in nature), areas such as downtown Toronto, would have a drastically different ambient spore load than an area with abundant natural vegetation, such as Thunder Bay. With the identification of a microbial growth issue dependent upon comparison to an outside benchmark sample, the potential ambient spore load present has to be factored. For the province of Ontario to arbitrarily assign a quantity or concentration of airborne mould spores that is not acceptable would be problematic to either end of the ambient spore load spectrum. Until further research determines what the safe limits of airborne mold spores to be exposed to are, its not likely that a regulation will be enacted.
Currently in Ontario, there are no regulations for mould remediation such as Ontario 278/05 which regulates Asbestos Abatement. The currently accepted guidelines (significantly different from a regulation) are the Canadian Construction Association Guidelines for Mould Remediation. What this means to the home owner with a mould growth problem is that they need to be extra vigilant in their selection of a Mould Remediation Contractor or Property Restoration Company. There is currently nothing more than the assumption of liability required for a contractor to designate themselves a qualified remediator. Plans are afoot to make mould remediation regulated similar to the way asbestos abatement is, but how long until that happens is just a guess. Caution when dealing with something that has the potential to impact the health of your family is always the best course of action. -Breathe Easy!













When do you need an indoor air quality professional?

The decision of when to contract the services of a indoor air quality professional, such as a trained mould remediation contractor, air quality assessment/ testing company is really determined by how long the occupants have been living with poor air quality, the potential scope of mould remediation required and the property's history of flooding.

The risk associated with exposure to certain types of mould (not just black mould) and poor indoor air quality has long been identified as causing everything from a mild allergic reaction to death. It should be noted that most mould (including some types of black mould) are primarily an allergen, and not necessarily always a toxin (although the potential exposure to dangerous toxic mould should not be taken lightly or ignored) and that each person's reaction to the mould will be determined by their particular sensitivity to it. I continually deal with customers (couple's generally) where one occupant has identified poor indoor air quality (be it from mould or other indoor conditions) that is virtually invisible to the other.

The simple answer to the question of when do you need an indoor air quality professional is; whenever a change in indoor air quality or environmental conditions within the building envelope is noticed. The common objection is often cost/price to this of course, but in reality the cost of delay in addressing potential risks is always greater than the price of preventing dangerous indoor air conditions. -Breathe Easy!









What can I do if I'm living with black mould?

Exposure to black mould generally causes an allergic reaction, save for the specific instances where you are exposed to quantities of toxic mould. The simpe solution to preventing the allergic response would be to limit the exposure to the mould containing environment. There are several strategies that can be employed to limit exposure:

1. Remove yourself from the environment that contains the mould.

2. Reduce the concentration of airborne microbial (mould) contamination that you breathe by ventilating the area sufficiently or scrubbing the air with HEPA-filtered air Scrubbing equipment.

3. Removing (remediating growth) or isolating growth from the building envelope (employing hoarding).

It is not uncommon for everyone in the home to not have the same response (or any response) to exposure to mould when the species present is not a toxic variety because everyone has a different response to exposure to an allergen.

-Breathe Easy!









Mould Behind Walls?

I am continually asked by my residential customers if they have to worry about mold behind drywall and insulation even though there are no visible signs of mold on the interior surfaces. The simple answer is there is no simple answer, but there are indicator signs to look for and testing methodology that can provide clues.

The typical scenario that leads people to be concerned about hidden mold is one that involves damp basements and the associated odor, without obvious visible signs. In some circumstances, a prior flood or water loss event, even if it was attended to structurally, had caused concerns about the potential for unseen mold.

When I inspect a property to assess potential factors affecting indoor air quality, I use the following checklist:

1. Identify any areas with signs of water damage or water intrusion.

2. Measure air temperature and relative humidity within the area of concern.

3. Measure moisture levels directly within building materials, wall and floor coverings.

4. Identify locations of drains if applicable and verify they are unobstructed or blocked.

5. In the case of basement areas with windows, inspect the window frame and sill area for evidence of water intrusion or failed window flashing.

Failing any direct evidence of mold growth within the area from the checklist inspections, the property owner has the following options:

1. Remove small sections of wall coverings for direct inspection of internal wall cavities.

2. Collect air samples (viable spore trap) to identify airborne mold spore contamination within the suspect area and an outside benchmark sample.

3. Utilize infra-red thermal imaging equipment to inspect hidden wall surfaces. The use of this technology illustrates the temperature differences within the building materials, however has limited efficacy in identifying mold growth used on it's own. This technology is recommended to be utilized in conjunction with direct inspection or bulk sampling to validate results.

Mold growth requires three conditions to be present in order to support growth, within wall cavities or otherwise. Moisture levels that exceed 30% directly measured within building materials or 60% relative humidity. An organic food source and a temperature range compatible with life. Without direct evidence of these conditions being present and without direct evidence of mold growth in the area of concern, it is possible that there is microbial growth unseen within the wall cavities, however it is not commonly observed. That being stated, if there is an odor of a microbial nature present, there is a source to be found. The excuse that basements smelling musty is normal is not a valid for not taking action.


When you are suspicious about whether there is mold present in your home that is not visible, take the following actions:

1. Consult a mold consultant to inspect the are in question, to determine if there are indicators that mold may be present but not visible. An inspection must be performed before the decision to collect bulk or air samples is made. Air sampling should be thought of as a powerful, yet inaccurate weapon. Firing it in a random direction may hit something, however is it guaranteed that it will hit what you were hoping? Non-viable mould spore trap sampling will find mould to be present because it is a naturally occurring organism present every where. Being able to determine if the spores sampled were caused by growth behind the walls is not possible without direct inspection.

2. Use a separate consultant to identify the mold problem than the one that you will potentially choose to remove it. Be open and honest with the testing consultant and tell them that you will use their definition of the scope of work to hire another contractor to perform the work. An honest professional will understand why the "separation of church and state" is required and won't even suggest them performing the work. A less reputable consultant will offer to lower the cost of remediation dramatically because they want to "help you out". The reality is, if a consultant is qualified and competent to identify the work required and still tries to undercut the competition out of a sense of charity, they likely know that the scope of work is smaller than what they are suggesting, but can make more money removing material that isn't required.

3. Hire a professional consultant to identify the issue, not a home inspector that also "does mold" or a contractor "in the business". Independent recommendations based upon unbiased fact that are peer reviewed is what is important.

The cost of hiring a consultant to identify the scope of work is a small portion of the total cost of a mold remediation. A successful remediation that is also the best value is one which removes only the material required.

-Breathe Easy!










Do it yourself mould testing: should I give in to temptation?

Mention of the words “air quality testing” can often bring feelings of dread and the assumption made that costs associated with having this work performed will be unreasonably high.  In my many years experience, there are better options for the home owner than ignoring the issue in the hopes that it isn’t too serious or too dangerous for their family and ignoring the issue in the hopes that it isn’t too serious or too dangerous for their family’s health.  The reality is, the identification of how serious an issue is will enable you to mitigate the risk to your family’s health until you are better able to deal with it.  Bulk sampling and the home test kits you purchase at the big box home improvement store will identify the presence of mould in most case however, they won’t identify the direct source of growth or enumerate the level of airborne mould spore contamination.  Think of them as a potential yes or no answer to your question of “do I have mould in my home?”  They won’t identify with any accuracy where the source of contamination is coming from or how large an area is affected and they won’t let you know what the ambient spore level is and the comparative levels present in your home are.  These are important items to know when your potential exposure to toxic substances is in question.   Many people are ignorant of the fact that mould is a naturally occurring organism that is present everywhere and that home sampling kits won’t be able to differentiate between normal ambient airborne spore contamination present in the home and elevated spore loading that is indicative of dangerous toxic growth.     

-Breathe Easy!









Balancing Energy Efficiency and Indoor Air Quality

The emphasis placed upon upgrading energy efficiency within existing residential properties in recent years has caused some homes to suffer from insufficient ventilation and poor air quality. A balance between indoor air quality, retrofit costs and energy conservation is required to ensure healthy living conditions remain in older homes being upgraded to today's building codes and standards.

Yesterday's Construction

In the typical Canadian or Northeastern U.S. home that was built in the period before the popularization of the R-2000 concept (1960-1980), insulation and ventilation standards were of secondary consideration to construction costs, due to the availability of inexpensive energy (heating/cooling costs). Insulation values comparable to our R-20 were not uncommon and still considered adequate for the climate's seasonal fluctuations. Window technology was often still reliant upon "storm" window use in the winter to supplement the high heat loss potential of wood frame windows and single glazing. As a boy in Ontario, I was continually told by my parents to "go outside and get some fresh air". The reality is, due to construction and material standards at the time, I was getting as much fresh air inside then as some children get outside now. The amount of 'accidental ventilation" that occurred in homes of the time and type through drafts caused by ill-fitting or poorly sealed windows and doors was significant and beneficial.

Todays Energy Upgrade Emphasis

In today's energy upgrading market, supplementing attic insulation, upgrading forced air furnaces and replacing old technology windows with modern low energy loss types is the rule of the land in older homes. Home owners may be at worst unwitting risking their health creating poor indoor air quality conditions or at best, merely transferring the destination of their heating dollar in the process. By upgrading windows and doors, eliminating drafts and sealing their home to reduce heating and cooling energy expense, home owners are eliminating a large portion of the "accidental ventilation" that aided indoor air quality and mitigated the effects of mould within the home. I continually encounter customers who discount the potential dangers of poor indoor air quality and mould based upon their experiences with homes prior to the R-2000 concept. Mould is a common and naturally occurring organism now as it was 40-50 years ago, today however, we live in homes effectively sealed to the outside that rely upon mechanical ventilation instead of accidental ventilation to reduce the concentration of contaminants and saturation of the indoor air environment. Increased humidity levels within the home cause condensation at the thermal break, making the addition of a Heat Recovery Ventilator (HRV) a requirement for all energy upgraded homes to avoid mould.

No Free Lunch

In the home heating and cooling battle, nothing is without compromise or cost: there are no free lunches. Home owners need to balance the following real world costs, with the anticipated energy savings:

Old Technology

Costs= Regular maintenance costs + heating/cooling energy costs.

New "Upgraded" Technology:

Costs= Replacement widows and doors + replacement or supplemental attic insulation + purchase, install and energy cost associated with a Heat Recovery Ventilator (HRV) + heating/cooling energy costs.

Given a long enough pay-back period and service life of the upgraded components, there can be a case made for breaking even on the investment in your home's energy efficiency but it depends upon the size of the home, the costs of the upgrades required, the climate and long-term cost of heating/cooling energy. If your home requires $15,000 in windows, $2,000 in insulation and $2,500 for a Heat Recovery Ventilator, how much does your energy consumption need to drop, and over how many years in order for you to recoup your $19,500 investment? Factoring in the cost of electricity for the HRV to function all day/everyday, if a home owner could save $100 on their monthly heating/cooling energy costs, they would be fortunate. At that rate, the pay back period for the upgrade costs required to save the $100 per month, it would take 16.25 years to break even on the $19,500 investment in your home, if no new windows or HRV's were required within that period.

The Air Quality and Energy Efficiency Balance

What is the solution for the home owner who needs lower heating and cooling energy costs, healthy indoor air quality and financial responsibility? The balance that I have struck in my own home, is applicable to all those home owners in the Northeast United States and Eastern Canada:

1. Upgrade attic insulation to R-50 and upgrade the attic ventilation to better than basic building code in your area to avoid attic mould.

2. Replace existing windows only as they fail and are required to prevent water intrusion. If a compromise has to be made for aesthetic reasons, replace curbside windows first.

3. Monitor indoor humidity levels to ensure they do not reach the mould danger zone of 60% or higher in non-summer months. Mould growth will occur on readily supportive organic materials caused by airborne humidity in homes with non-summer seasonal humidity above 60% for greater than 24-48 hours. Mould growth supported by humidity often occurs first in areas near outside walls at ceiling level of homes, based upon warm (in this case warm and moist) air rising. Only invest in the purchase and running of an HRV when humidity control is required to control mould growth.

4. Manage your heating and cooling costs through use of programmable thermostats, turning your heat down and your A/C up. Consider the use of passive cooling methods such as blinds, awnings and reflective window films.

Remember, the contractor that wants to save you money by having you purchase new windows, doors, insulation, furnaces and Heat Recovery Ventilators are not doing it as a public service, they are doing it to make money. Strike a balance between estimated savings over the long-term, the investment required in the short- term, and the potential health risk associated with poor indoor air quality caused by insufficient natural ventilation

    -Breathe Easy!







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