Indoor Air Quality

MWI Consultants performs investigations for industrial/commercial/residential air quality issues, with practical, cost-effective solutions to improve your indoor environment.

Indoor Air Quality has become a significant environmental issue, whether it is at home or at the workplace. Most of us spend the vast majority of our time indoors, and poor air quality can aggravate asthma and other lung conditions, particularly in the very young, the elderly and people with sensitivities. The number of complaints and potential issues have increased in recent years with increased building tightness and energy conservation measures that reduce the amount of outside air supply, the growing use of synthetic materials, and the increase in the prevalence of asthma, allergies and other chemical sensitivities.

For office environments, office equipment (e.g., photocopiers, laser printers, computers), cleaning products, poorly maintained heating, ventilation and air conditioning (HVAC) systems, inadequate fresh air supply and outdoor air pollution can increase the level of indoor air contamination.

For residential situations, homes can contain many substances that may be hazardous to our health. Indoor air pollutants range from minor irritants such as dust and animal dander, to major irritants such as mold growth and chemical vapours, including volatile organic compounds (VOC) that may be emitted from building materials and furnishings. Attached garages or poorly vented furnaces or water heaters may lead to an accumulation of carbon monoxide.

All of our indoor air quality assessments are customized to suit each individual situation, and include the preparation of a comprehensive report summarizing the laboratory results obtained, if applicable, any relevant observations as well as recommendations to improve your indoor environment when issues are noted. We will work with you to determine the potential concerns, and to develop a practical, cost-effective plan to evaluate the indoor air to ensure that there are no issues.

Our clients have included property managers, school administrators, health and safety professionals, building maintenance managers, insurance companies, general contractors, employers, federal and provincial government agencies.

If you have a problem or suspect you may have some indoor air quality issues but are unsure as to how to proceed, please let us know using the Contact Us page.

An indoor air quality assessment could include any or all of the following, depending on your requirements:

General inspection for problem areas and common issues

Every indoor air quality assessment would include a thorough visual inspection for some common issues, such as evidence of moisture damage, the presence of materials that may contain asbestos and issues related to HVAC equipment.

In some cases, air quality issues may be intermittent, short-term or may only be present on certain days or at certain times. In these cases, monitoring over a period of time would be able to provide a clear picture of the overall level of indoor air quality over a period of time. Monitoring for carbon dioxide (CO2) can determine if an adequate amount of fresh air is being supplied in relation to the number of occupants, which is a common cause of IAQ complaints in office settings.

Moisture Checks

Moisture and high humidity conditions (or dampness) are associated with several indoor air quality issues including the potential for mould growth, increased levels of dust mites, bacteria and bacterial endotoxins. We use a non-destructive pinless instrument that can detect residual moisture in walls and other areas, and also use thermal imaging to detect areas of concern, including areas where there is a lack of insulation or cold air penetrating into buildings during the winter.

Air Quality Monitoring

Monitoring over a short or longer period can detect issues which may not always be present.

Areas can be monitored using a data logger which can record reading for Temperature/Relative Humidity, carbon dioxide (CO2), carbon monoxide (CO), nitrogen dioxide (NO2), hydrogen sulfide (H2S) and Volatile Organic Compounds (VOCs).

Volatile Organic Compounds

Volatile organic compounds (VOCs) can represent a significant health concern, with individuals becoming sensitized to particular chemicals either at home or the workplace. General VOC levels can be quickly spot-checked using a portable device or samples can be taken to identify the specific chemicals present in the air.

Airborne mould sampling (viable and non-viable)

We provide sampling and consulting services for airborne mould concentrations. For more information, refer to the “Mould Inspection, Sampling and Remediation” page.

Dust and Particulates

Monitoring for dust and particulate can serve as a good indication of the effectiveness of the air handling and filtration systems. Longer-term exposure to smaller particles (especially ultrafine particulate) can cause respiratory issues. We use a Met-One laser particle counter to determine general dust and particulate levels throughout your home or work environment. All data is tabulated and summarized in the written report. Different areas can be sampled to provide for useful comparisons, and longer term monitoring can also be done to determine differences over a period of time.


In some cases, testing for specific allergens can be useful, especially when symptoms reported are consistent with allergic responses. Different types of allergens can be sampled for including cockroach, cat, dust mite, rat, mouse, and dog. Sampling consists of collecting dust or dirt from carpets, furniture or other areas and analysis by a qualified laboratory, generally using an enzyme-linked immunosorbent (ELISA) assay.


Radon, which is a colourless, odorless, radioactive gas that occurs naturally from the natural breakdown of uranium in soils and rocks can migrate into buildings and accumulate through dirt floors, cracks in concrete, sump pits, joints, basement drains or other areas. Radon is a known carcinogen and may lead to an increased risk of lung cancer from chronic exposure. Monitoring for radon consists of leaving a small instrument in the basement area for a period, and determining levels present. . If radon is discovered, there are steps that can be taken to minimize its impact.


Many older homes in Canada are decorated with lead-based paint. Removing or disturbing this paint as part of a renovation project could expose people in the home to serious health risks. Exposure to lead can cause anemia and it can also damage the brain and nervous system, resulting in learning disabilities.

The presence of lead can be determined quickly using colorimetric lead-check swabs or samples can be taken and analyzed by a qualified laboratory to determine lead content accurately, depending on what the situation warrants.