Improving indoor air quality of public buildings in Canada

The Canadian Government tells us that Canadians spend 90% of their time indoors, which should mean improving indoor air quality of public buildings is important. Unfortunately, poor indoor air quality is a common problem in government workplaces and public buildings. Public buildings include; recreational facilities such as hockey rinks, schools, libraries, government offices, etc. These buildings have different requirements in terms of dealing with indoor air quality and it is not possible to have a standardized one-size-fits-all approach. 

There are many different ways we can improve indoor air from better air filtration to public awareness campaigns. This article will detail ways in which we can better protect our health when we breathe indoor air. 

Improving indoor air quality in public buildings. This infographic displays the problems and solutions of IAQ in public buildings.

Canadian government study on indoor air quality

Health Canada states, “A changing climate means not just an increase of extreme weather events, such as floods and wildfires, but also an increase in allergens. Elevated outdoor levels of aeroallergens, such as pollen, can infiltrate into buildings and affect allergic diseases. Good indoor filtration and ventilation can help you protect your health in a changing climate.”

A recent study by the government of Canada on indoor air quality has found that public buildings in Canada are not meeting the standards set by the National Building Code. The study, conducted by Health Canada, looked at a sample of government-owned and leased buildings across the country.

The findings showed that many of these buildings have poor indoor air quality, which can lead to health problems for occupants. The indoor air quality of public buildings has been a problem for many years. Adverse health effects from indoor air pollution are a significant global public health concern. 

A variety of factors can contribute to poor indoor air quality, including:

  • Inadequate ventilation
  • Poor air filtration, low-quality air filters used
  • Poor maintenance
  • High/low temperatures
  • Humidity- RH higher or lower than the recommended 35-50%
  • Harmful chemicals and materials in furnishings and equipment, volatile organic compounds (VOCs)
  • Airborne pollutants 
  • Many common cleaning products can also release harmful chemicals into the air

How does indoor air quality affect health?

Poor indoor air quality can cause a variety of health problems, including respiratory diseases. It can also aggravate pre-existing conditions. Indoor air pollution can even lead to heart disease and cancer.

In the United States, the Environmental Protection Agency (EPA) has stated that Health effects associated with indoor air pollutants include irritation of the eyes, nose, and throat as well as headaches, dizziness, and fatigue.

Buildings downtown with a clouds in the sky and the Sun reflecting on the windows of the building

What contaminants exist in public buildings?

The following unhealthy contaminants may exist in public buildings:

  • Asbestos
  • Biological Pollutants such as bacteria, mould, mildew, viruses, dust mites
  • Carbon Monoxide (CO)
  • Formaldehyde/Pressed Wood Products.
  • Lead (Pb)
  • Nitrogen Dioxide (NO2)
  • Sulfur Dioxide (SO2)
  • Pesticides
  • Ozone (O₃)
  • Radon (Rn)
  • Acrolein
  • Particulate matter (inorganic) 

“The link between some common indoor air pollutants (e.g., radon, particle pollution, carbon monoxide, Legionella bacterium) and health effects is very well established.” –Environmental Protection Agency

  • Radon is a known human carcinogen and is the second leading cause of lung cancer
  • Carbon monoxide is toxic, and short-term exposure to elevated carbon monoxide levels in indoor settings can be lethal
  • Episodes of Legionnaires’ disease, a form of pneumonia caused by exposure to the Legionella bacterium, have been associated with buildings that have poorly maintained air conditioning or heating systems
  • Numerous indoor air pollutants are “asthma triggers,” meaning that some asthmatics might experience asthma attacks following exposure


Inadequate ventilation, materials that release gases and particulates- especially legacy materials such as lead-based paints and asbestos, and poor air filtration can all lead to poor indoor air quality. 

Also, carbon monoxide in office buildings can lead to serious health problems, but it is often not detected because office buildings are not required to have CO detectors.

Volatile organic compounds (VOCs) can present challenges because companies that test for their presence only test for limited gasses, but with a myriad of VOCs out there, many VOCs can escape detection. 

How do you improve indoor air quality in HVAC?

Sometimes the HVAC system can actually cause indoor air quality to suffer. For example, when ventilation air filters become moist, or when microbial growth is left unchecked from uncontrolled moisture in air ducts, HVAC systems can be sources of pollutants. 

Also, many property managers or facilities managers purchase poor-quality or inefficient air filters which work well when installed, but then quickly lose efficiency causing indoor air quality to deteriorate. It is best to consult an air filter expert to understand the type of air filter that you need for your public building or facility, as each type of building has unique needs. 

HVAC maintenance and public building indoor air quality

HVAC maintenance must also be considered when evaluating indoor air quality in public buildings. Poorly maintained HVAC systems can become contaminated, can leak, or can contain blockages preventing air from flowing freely. These systems must be checked regularly and parts must be replaced when needed in order to ensure proper function. 

Outdoor air quality impacts indoor air quality

VOCs such as carbon monoxide and other gases affect indoor air quality when polluted outdoor air enters the HVAC system. If high-quality, long-lasting, efficient air filters are not used, contaminated air from outside can infiltrate indoor environments and can easily circulate and negatively impact the health of public building occupants. People can become sick without knowing the source of the illness. 

Space planning and indoor air quality

Furniture or computer equipment is often placed in areas that block circulation of air. Areas that are cluttered impede air circulation the most. They also make it more difficult to keep areas clean and disinfected. HVAC specialists should be consulted when planning office layouts (e.g. avoiding placement of cubicle partitions which block airflow), or arranging public buildings to ensure that air flows freely and effectively. 

Other considerations

There are certain areas in buildings called “dead zones” where airflow is severely restricted such as stairwells and some rooms in public buildings for example, dressing rooms in recreational facilities. It would be advisable to use portable air purifiers in those instances because HVAC systems cannot always supply adequate airflow. 

How do you improve air quality in a public or government building? -Building design and organization that improves IAQ 

Public buildings are places where people gather for work, leisure, or other activities. The indoor air quality of these buildings can have a significant impact on the health and well-being of occupants. 

To ensure the indoor air quality of public buildings is up to standards, sustainable building practices should be used. These practices help to reduce the amount of harmful pollutants in the air and improve ventilation. In addition, building codes for indoor air quality should be followed to ensure that public buildings are safe for occupants.

Some sustainable building practices that can improve indoor air quality include:

  • Using low-emitting materials
  • Increasing ventilation rates
  • Improving air filtration

Associations such as Building Owners and Managers Association (BOMA) and the Canada Green Building Council (CGBC) have put together a framework to determine best practices for designing and maintaining sustainable buildings. Indoor air quality is central to a sustainable building approach. Guidelines such as minimum air changes per hour or best practices to decrease concentrations of pollutants are carefully outlined by these associations. Guidelines for air filtration for property managers

Do public buildings have better indoor air quality than private buildings?

Indoor air quality is an important consideration for public buildings. Some building types are better than others for indoor air quality. Most people tend to believe that office buildings and schools have better indoor air quality, while factories and warehouses have poorer indoor air quality. Although it may be the case most of the time, the reverse could be the case. Different buildings have different needs and requirements based on space, occupancy, and original design.  Cookie-cutter approaches often fail in ensuring adequate IAQ, as each building must be assessed individually. 

By following sustainable building practices and adhering to best practices for indoor air quality, public buildings can be a safe and healthy environment for the public and for public sector employees. 

Indoor air quality of Recreational facilities

The Ontario Recreational Facilities Association states, “Indoor air quality problems in arenas can be caused by many factors. Ventilation system deficiencies, overcrowding, tobacco smoke (from poor policy enforcement or having smoking areas too close to intake air vents), microbiological contamination, outside air pollutants, cleaning chemicals, ultrafine particulate matter (UFP) and refrigerants as well as off‐gassing from materials and mechanical equipment.  Elevated levels of carbon monoxide and nitrogen dioxide in ice facilities have been specific causes for alarm in the past.  Ice resurfacing equipment has often been identified as the primary contributor to poor IAQ in arenas…a building ages as well, and in the cool, damp environment typical of arenas, corrosion and mould can lead to additional IAQ problems.” 

ORFA also states that children in recreational facilities can breathe at a much higher rate than adults, and in doing so they can also absorb more harmful particles into their bodies, causing greater harm.  Also, recreational facilities may pump in a great amount of air from the outside on days when outdoor air quality is poor due to smog. This could result in the polluted air from outside being trapped inside for long periods. 

Air filtration in Educational facilities

The COVID pandemic exposed a lot of problems with indoor air quality in Canadian schools. Hundreds of schools in Canada did not have integrated ventilation systems and their only ventilation method is through opening doors and windows. Since Canada has a cold climate in winter, opening windows and doors in winter creates uncomfortable drafts and can result in very cold temperatures indoors. It is difficult for students to concentrate when they are exposed to discomfort caused by cold. Increasing heat from the HVAC system to compensate for this could lead to more problems as the system has to work harder and could easily falter. 

Students at their desks, studying in a classroom

Although the Canadian government invested $150 million for better ventilation for schools in 2021, there is still more to do to improve IAQ in schools. 

Related: How Can School Officials Improve IAQ?

Air quality and Public Transportation 

Public transportation stations and vehicles (buses, trains, subways, ferries) can be a conduit for airborne virus transmission as well as a source for emitting dangerous particles. 

The Canadian Government states, “The main pollutant of concern is particulate matter (PM) pollution, particularly the “fine” fraction (PM2.5). It is well-established that PM 2.5 can cause adverse health effects, including increased mortality and the development of heart and lung disease.”

There are also VOCs, nitrogen dioxide and other pollutants on buses, trains, and ferries. When passengers embark and disembark, they can bring in pollutants from outside and particularly during rush hour periods, passengers can be exposed to a great deal of harmful substances on public transportation. 

The Government concluded that routinely monitoring subway and rail air quality is important to detect changes in PM concentrations. It pledged to operate and optimize forced (mechanical) ventilation systems based on usage, instead of using only natural ventilation. It also pledged to improve air filtration systems in stations and on vehicles.

The Ontario Public Health Association conducted a study that found: 

“Children can be exposed to significant amounts of air pollution while traveling on school buses,” said a team of researchers from the Ontario Public Health Association, “The OPHA study found that school buses, which are largely fuelled by diesel, can be self-polluting, with emissions from tailpipes and engine compartments polluting the air onboard.”  

The study also found that local ambient air quality, traffic patterns, wind direction, and the position of the vehicle’s windows influence the concentration of pollutants inside a school bus. Research demonstrates that the indoor air quality inside of school buses is significantly worse than the outdoor air, with concentrations of pollutants often measured several times higher than concentrations outdoors. 

Researchers were most concerned about fine particulate matter and diesel particulate matter, which are linked to a range of health effects, including:

  • Aggravation of asthma, leading to increased severity and frequency of attacks.
  • Increased likelihood of developing respiratory infections. 
  • Reduced lung function.
  • Increased emergency room visits, hospital admissions, and premature deaths. 
  • Increased incidences of chronic respiratory and cardiovascular diseases, including lung cancer. 

OPHA notes that such pollution levels are especially troubling because children’s developing lungs are more sensitive to the health effects of air pollution. Asthmatic children are especially vulnerable to air pollution.  

Another study by OPHA found that air filters provide crucial protection for children on school buses. When a diesel particulate filter was installed on the exhaust system of school buses, on-board pollution exposure could be almost eliminated. 

While the vast majority of school buses in North America run on diesel, there are alternatives. Biodiesel can be used in many of these school buses. BIodiesel can even reduce bus operating costs by up to 20%. The best approach would be to use electric school buses as they are zero-emissions vehicles and would not self-pollute. Electric buses can reduce operating costs by 50%. 

  • Prince Edward Island, along with the Federal Government is investing millions in electric school buses to replace their diesel fleet in 2022-2023. 
  • Toronto Transit Commission (TTC), in April, ordered 270 new hybrid-electric buses to include in its fleet;
  • Ottawa’s OC Transpo says it’s adding 26 new battery-electric buses by the end of 2023;
  • The City of Regina approved in May the adoption of the city’s first Transit Master Plan that will add electric buses to its transit fleet
  • Saint John Transit presented to local city council in April plans for electrifying its buses

Although using electric buses for transportation of students and the public will eliminate the adverse effects of diesel fuel inhalation, buses will still absorb polluted air from outside. Cabin air filters will still be necessary. 

Space and preventing overcrowding 

Space and overcrowding can also affect indoor air quality. High ceilings can impact air quality, as they can trap pollutants and allow them to build up over time. With overcrowding, people can bring in pollutants from outside air, airborne viruses can easily spread, and air circulation can be impeded in conditions where too many people occupy a space meant for far fewer people. Most HVAC systems are not designed for excessive crowds or lineups for government services in government buildings, or for densely packed working areas. 

How to prevent overcrowding in public buildings for better indoor air quality

Buildings and public facilities are designed for a certain capacity. Each percentage above the designed capacity will cause indoor air quality to suffer.

To ensure good indoor air quality in public buildings, it is important to consider all of these factors and take steps to mitigate any potential problems. The American Society of Heating, Refrigerating and Air-Conditioning Engineers in Standard 62.1, Ventilation for Acceptable Indoor Air Quality, recommends a wide range  of outdoor air per person for public buildings, measured as CFM/person. 

Ventilation systems

Public building ventilation plays a crucial role in the health of building users. 

The main purposes of ventilation are to: 

  • dilute and expel contaminants from indoor air 
  • increase the amount of oxygen inside public buildings
  • help regulate temperature
  • bring up or bring down humidity in buildings to healthy levels

Natural ventilation relies on open windows and doors for increased airflow, and mechanical ventilation relies on fans and ducts which force air in, to increase airflow through public buildings and facilities. Most public buildings and facilities use a combination of natural ventilation and mechanical ventilation. Also, for example, when there are more children present in a school, mechanical ventilation can be ramped up to increase airflow and then reduced when there are no students and teachers present. 

Because there are so many different types of public buildings; arenas, research laboratories, schools, gyms, there are different needs for each of them. For example, laboratories require ventilation to remove contaminants in the air for machines and reduce the presence of hazardous particles in the air for lab users. Schools may have overcrowding issues to deal with and require more ventilation than other facilities. 

Because ventilation and air filtration requirements are ever evolving and adapting to building design changes and arising needs, it is best to consult with a ventilation and air filtration specialist to ensure that the indoor air quality of your public building or facility is high. 

What are 10 ways to reduce indoor air pollution?

  1. Keep indoor air clean by regularly cleaning floors, carpets, and upholstery
  2. Use an indoor air purifier in problem areas to remove pollutants from the air
  3. Limit your use of cleaning agents and other chemicals
  4. Ventilate your office space, school, or building, to get rid of indoor pollutants
  5. Get rid of mold and mildew growths immediately
  6. Keep indoor plants in your building to help filter the air naturally
  7. If the air outside is not polluted in your area, use natural ventilation when possible by opening doors and windows
  8. Regularly check for leaks in your building’s heating and cooling system as these can release pollutants into the air
  9. Address any sources of contamination, leaky pipes, or moldy surfaces. 
  10. Do not exceed rated occupancy

What is the Canadian Government doing to improve indoor air quality?

The Government of Canada is taking steps to improve air quality in public buildings through initiatives such as The Clean Air Act which sets national standards for indoor air quality.

Which government agency is responsible for the Clean Air Act? 

The Clean Air Act in Canada is the responsibility of the government agency Health Canada. Health Canada works to protect the health of Canadians by ensuring that the air we breathe is clean and safe. Part of their work includes setting standards for indoor air quality in public buildings.

The government has set up other programs to help improve indoor air quality in public buildings, including the Indoor Air Quality Strategy and the National Air Quality Strategy. These programs are designed to reduce exposure to indoor air pollutants, improve ventilation and filtration systems, source control, and increase awareness of indoor air quality issues.

Other Canadian guidelines for IAQ

The Canadian Centre for Occupational Health and Safety (CCOHS) states, “Many Canadian jurisdictions do not have specific legislation that deals with indoor air quality issues in non-industrial workplaces. In the absence of such legislation, the general duty clause applies. This clause, common to all Canadian occupational health and safety legislation, states that an employer must provide a safe and healthy workplace. Thus, making sure the air is of good quality is the employer’s duty.”

The government is also working with industry and organizations to develop voluntary guidelines for improving indoor air quality in public buildings. These guidelines will help ensure that public buildings are safe and healthy places to work, learn, and play.

What more can the Canadian government do to improve indoor air quality in public buildings?

There are a number of other things that government agencies can do to improve indoor air quality in public buildings. Some simple steps include:

  • Ensuring that all public buildings have adequate ventilation through more mandatory measures such as establishing more ambitious minimum indoor air quality requirements
  • Increasing the inspection frequency of air filters and air ducts in public spaces
  • Enacting laws to reduce air pollution sources
  • Doing more outreach to the public on indoor air quality issues and how to improve IAQ

For more information, please visit Health Canada’s website:

For further information on how to improve indoor air quality in public buildings, please use this contact form and an air filtration expert from Camfil will answer any questions you may have. 

About Camfil Canada Clean Air Solutions 

For more than half a century, Camfil has been helping people breathe cleaner air. As a leading manufacturer of premium clean air solutions, we provide commercial and industrial systems for air filtration and air pollution control that improve worker and equipment productivity, minimize energy use, and benefit human health and the environment. Read more about Camfil Canada


Sources, further reading: Ontario Recreational Facilities Association

Media Contact:

Phillip Ilijevski

Camfil Canada Inc.

T: 437-929-1161


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