How can I tell if there is an indoor air quality problem?
A good basis for suspecting an indoor air quality problem is by comparing how you feel when in the area of concern and when you are away from the area of concern.  Note how you feel when you are at home, at your workplace, on holidays or if you stayed at someone else’s place for a period of time.

Did your symptoms improve when you left your home or workplace? What happened when you came back? Some people can tell by being away for even a day. However, the symptoms may be so severe that they do not change with location.

If dealing with a workplace, are other individuals in the same vicinity experiencing the same types of symptoms?  At home, observe if guests or visiting family experience unusual symptoms while staying with you.

People with allergies react to contaminants faster than those without allergies.

You can also observe all areas of your home or workplace.  Look for evidence of dampness or staining or presence of unusual odours.

I think I have an indoor air quality problem — what can I do?
It is important that the problem be identified. You may be able to pinpoint the location or source of the problem in the house. You can determine if the problem is present all the time, only at certain times or only at certain times of the year. Observe whether the symptoms become aggravated by any particular activities.

Once you have zeroed in on a problem, look up the suggested solution and determine if it is appropriate. You can do simple, inexpensive measures. However, consider getting professional advice before implementing corrective measures that are involved or costly. You could end up spending more money doing renovations that will not solve the problem.


I would like to have someone test the air in my house for mould.
Testing the air in your house will not give you the information you need to solve a problem. An inspection by a trained investigator will provide you with more useful information, such as whether there is a mould problem or not, the causes or sources of moisture and how to correct them. An air sample, on the other hand may tell you the kinds of moulds that may be present in the air. To find out where the moulds are coming from, samples from different parts of the house would need to be taken. The results will not tell you the action needed to correct the problem.

Is it safe for me to clean the mould myself?
It depends on how much mould you are dealing with. A small area of mould occupies approximately 1 square meter. You can clean this yourself. Please refer to About Your House “Fighting Mould: The Homeowner’s Guide” and Clean up Procedures for Mould in Houses. You may need a contractor trained in cleaning mould to deal with more extensive areas.

Is bleach recommended for cleaning?
Bleach is NOT necessarily recommended. The presence of organic materials, the pH (acidity/alkalinity) of the water, the surface material and contact time affect the effectiveness of bleach for disinfection. Since these factors are not generally controlled, bleach cannot be relied upon for disinfection. The most compelling reason for advising against bleach is that fumes are harmful but in addition, overuse of bleach will result in increased releases of chlorinated effluents which can be harmful to the environment.

My basement is chronically damp. Is there something I can do?
The first step is to clear the basement of stored materials that are no longer needed. Clothing, cardboard boxes, paper, books, pieces of wood, etc. absorb moisture and become places for mould to grow. Discard as much materials as possible to make it easier to clean the basement. The second step is to determine why the basement is very damp. Is there a leak or is water seeping in through the walls or floor? The latter would require steps to stop the water from coming in and may involve major work. Some simple things you can do include making sure downspouts have extensions and soil around the foundation slopes away from the house. If these do not make any difference than you need someone to advise you whether work around the foundation is needed.
Moisture could also come from interior sources and these have to be identified and corrected. Common sources are using a humidifier, a hidden plumbing leak, line-drying clothes or venting a clothes dryer into the house.

Control humidity in the basement by using a dehumidifier. If buying one, choose one with a high capacity that can operate at a low temperature and is rated to be energy efficient. Operate the dehumidifier from spring to fall. A dehumidifier would serve as an interim measure, but bear in mind that it may not be sufficient to stop mould from growing until exterior sources are corrected.

Will a portable air purifier help with a mould problem?
The most effective solution for a mould problem is to identify the causes and eliminate them. An air purifier can reduce airborne mould spores, but would only be effective if the rate these are removed is faster than the rate they are produced. Very little benefit may be obtained if the area being cleaned is too large for the unit to handle or there is a mouldy carpet or there is a strong hidden mould source in the house.

Would a HEPA furnace filter help with a mould problem?
A HEPA (High Efficiency Particulate Air) filter is unlikely to make much difference. In the first place, a one-inch medium efficiency pleated paper filter has adequate filtering capability for the majority of homes. It can replace typical throwaway furnace filters with no required modifications to the ducting. A HEPA filter can more effectively trap finer particles than a medium efficiency filter, but it is more than what is needed in most homes where pets, carpets and other sources of particulates may still be present. To install a HEPA filter, the cold air plenum would need to be modified to accommodate the thickness of the HEPA filter. Because of the increased resistance to air flow, the blower would also have to be upgraded. Lastly, A HEPA filter cannot be replaced as frequently as the pleated paper filters because of the higher cost. It can end up accumulating a lot more dirt than a less efficient filter before it gets replaced.

Is a HEPA vacuum cleaner useful for moulds?
A HEPA vacuum cleaner is a useful investment. It captures fine particles that a typical vacuum cleaner would blow back into the air. Better-built HEPA vacuums have tighter housing that prevents these fine particles from leaking out. An alternative to HEPA vacuum cleaners is a central vacuum cleaner that exhausts to the outside.
If you have a mould problem in your house and you cannot get the problem fixed immediately for one reason or another, vacuuming frequently with a HEPA vacuum cleaner is recommended as an interim measure. Mould spores are in settled dust. Your exposure to mould is lowered by reducing the amount of dust.

Is an HRV suggested to solve a mould problem?
An HRV cannot correct an existing mould problem. The mould has to be cleaned up and the cause has to be corrected. An HRV would then enhance the quality of the air. Installing an HRV by itself without prior cleaning and correcting the cause would have a similar effect as airing the place by means of an open window.
Operating an HRV controls moisture in the home during the cold months and supplies fresh air into the house. During the warm months, a dehumidifier should be used to reduce humidity levels in the basement.

I have noticed mould in my apartment. What can I do?
Report the mould to your landlord or property manager. After you have notified your landlord, you can clean small areas of mould yourself. Wear a respirator and gloves. Let the landlord know if the mould comes back after cleaning. The underlying problem has to be identified and corrected.


What is asbestos?
Asbestos is a natural mineral with unusual qualities. It is strong enough to resist high temperatures, chemical attack and wear. A poor conductor, it insulates well against heat and electricity.
Asbestos crystals become long, flexible, silky fibres, so it can be made into a wide variety of forms. It can be spun into yarn, woven into cloth or braided into rope. Asbestos can also be added to materials as diverse as cotton and cement.

This combination of properties gives asbestos performance capabilities that are difficult to match.

What has asbestos been used for?
Asbestos has been used in hundreds of applications and products over the past 4,500 years. The ancient Greeks wove it into oil lamp wicks, funeral shrouds and ceremonial tablecloths. During the 1800s, it insulated the hot engines, boilers and piping that powered the Industrial Revolution.

For half a century, until the 1980s, asbestos was used in office buildings, public buildings and schools. It insulated hot water heating systems, and was put into walls and ceilings as insulation against fire and sound.

Asbestos has also been widely used in transportation and electrical appliances, frequently mixed with, and encased in, other materials.
Asbestos has also been found in many products around the house. It has been used in clapboard; shingles and felt for roofing; exterior siding; pipe and boiler covering; compounds and cement, such as caulk, putty, roof patching, furnace cement and driveway coating; wallboard; textured and latex paints; acoustical ceiling tiles and plaster; vinyl floor tiles; appliance wiring; hair dryers; irons and ironing board pads; flame-resistant aprons and electric blankets; and clay pottery. Loose-fill vermiculite insulation may contain traces of “amphibole” asbestos.


What health problems are associated with exposure to asbestos?
Asbestos poses health risks only when fibres are in the air that people breathe. Asbestos fibres lodge in the lungs, causing scarring that can ultimately lead to severely impaired lung function (asbestosis) and cancers of the lungs or lung cavity.

Concern for the health of asbestos workers was expressed as long ago as the late 1800s.  The risks became more evident in the late 1960s, when workers who had been heavily exposed 20 to 30 years earlier showed increased incidence of lung disease.  Occupational exposure is now strictly regulated by provincial governments.

How to minimize the asbestos risks in the home?
If you do not know if products in your home contain asbestos, the materials can be evaluated visually or can be sampled and analyzed by a laboratory.

If there is asbestos, then only qualified asbestos abatement contractors should be used to complete any removals.  If you are planning renovations, ensure that materials are tested ahead of the work.  Most reputable contractors are aware of this requirement, but you should ask if you are uncertain.

When disturbing an asbestos product, maximum precautions must be taken to safeguard the workers and anybody else who may be nearby.

Some potentially hazardous activities related to asbestos can include:

  • Disturbing loose-fill vermiculite insulation (Zonolite) which may contain asbestos
  • Drywall removal, with asbestos in the joint compound
  • Removing deteriorating roofing shingles and siding containing asbestos, or tampering with roofing felt that contains asbestos
  • Ripping away old asbestos insulation from around a hot water tank
  • Sanding or scraping vinyl asbestos floor tiles (VAT)
  • Breaking apart acoustical ceilings tiles containing asbestos
  • Sanding plaster containing asbestos, or sanding or disturbing acoustical plaster that gives ceilings and walls a soft, textured look
  • Sanding or scraping older water-based asbestos coatings such as roofing compounds, spackling, sealants, paint, putty, caulking or drywall
  • Sawing, drilling or smoothing rough edges of new or old asbestos materials

Workplace Exposure Assessments

When does my workplace require a workplace exposure assessment?
The answer would depend on where your business is located.  As MWI Consultants is located in Winnipeg, Manitoba, the following answer will apply to businesses located in Manitoba.
According to the Manitoba Workplace Safety and Health Regulations (M.R. 217/2006, Part 36), every workplace where a chemical or biological substance is present is required to perform an assessment to determine if substances present may create a risk to workers at the workplace.  This does not necessarily mean that sampling and laboratory analysis is required in every instance; this simply means that every employer has a responsibility to perform an assessment of their workplace in order to determine whether procedural controls or personal protective equipment (e.g., respirators) are required in order to protect the health and safety of their employees.

What services does MWI Consultants provide?
We can provide sampling, testing and interpretation of the results to determine whether or not workers are exposed to chemical hazards in the workplace that exceed allowable limits (e.g., ACGIH TLV).  We will make recommendations regarding air handling and ventilation systems or suitable respiratory protection, as determined by the circumstances.
We take a logical approach to these and try to work with employers to develop reasonable solutions to any issues.

Which chemical or biological substances need to be assessed?
The easiest way to determine which substances need to be assessed is to develop a list of all chemical or biological substances present in the workplace.  For most workplaces, the MSDS binder will contain most of the applicable substances.  A review of manufacturing processes would also be warranted in order to determine if chemicals are produced (off-gassing, emissions) at any given point, and workplace inspections would also be appropriate in order to ensure that the list is comprehensive and includes consumer products for which an MSDS may not be available.

How do I assess the risk of a certain chemical or biological substance in my workplace?
Once a list of chemicals or biological substances present in the workplace has been created, determine how each product is being used in the workplace and the means of exposure.  For non-airborne exposure risks, control measures (gloves, goggles) should be implemented to minimize the risk.  For airborne exposure risks, each workplace is responsible for establishing Occupational Exposure Limits (OELs), which are generally based on the ACGIH (American Conference of Governmental Industrial Hygienists) handbook that lists TLV (Threshold Limit Values) for many chemicals.