Resource
Indoor air quality
Canadians spend an average of 90% of their time indoors at home, work and in recreational environments, so our indoor environment plays an important role on our health. Whether at home, work or other indoor spaces, understanding the factors that can affect indoor air quality can help us take actions to improve our indoor environment.
Impacts and improvements
Indoor air quality can be impacted by:
- Moisture build-up, dampness, and/or water leaks
- Inadequate ventilation
- Poorly maintained heating and ventilation systems
- Building materials and furnishings such as newly installed cupboards, flooring and carpets
- Household cleaning and maintenance products
- Vehicle emissions from attached garages
- Hobbies or activities such as metal or wood-working
- Indoor combustion including wood burning fireplaces and gas stoves
- Outdoor air pollution
Indoor air quality can be improved by:
- Controlling the source of indoor air contaminants
- Improving ventilation and/or filtering the air
- Preventing/removing moisture build-up
- Reducing infiltration of outdoor air pollutants to the indoors
For more information on indoor air pollutants and improving indoor air quality in your home, please visit Health Canada’s –Air quality and health page.
Ventilation
Ventilation is supplying fresh outdoor air to an indoor environment and diluting or removing stale indoor air. Poorly ventilated spaces can allow indoor air pollutants to build up and potentially impact health. On good air quality days (most days in our region), bringing in outdoor air can dilute the concentration of pollutants indoors.
Ventilation methods such as natural ventilation (i.e. air moving through opened windows and doors), and mechanical ventilation systems can greatly improve indoor air quality. There are different types of mechanical ventilation such as bathroom fans, kitchen exhaust hoods and HVAC (heating, ventilation and air conditioning) systems within a building to allow ventilation and adequate air change rates.
It is also important to consider outdoor air quality when operating a ventilation system, and reduce entry of outdoor air pollutants. This is especially important during wildfire smoke events. Outdoor air pollution can come from several sources including wildfire smoke and traffic. Outdoor air pollution can substantially impact indoor air quality because much of this pollution can move indoors.
- During wildfire events, it is important to increase air filtration and potentially adjust ventilation so less outdoor air is moved inside. Windows and doors to the outdoors need to be closed for air filtration to be most effective. (For more information, see our Wildfire Smoke guidance document for schools and childcare facilities).
- For buildings located in an area with poor air quality year-round (such as near a busy road), consider enhancing filtration in the HVAC system to help remove pollution before it comes indoors. (For more information, see our Traffic-Related Air Pollution guidance document for schools and childcare facilities).
For more information on ventilation and CO2, visit our Ventilation and Indoor Air Quality guidance document for schools and childcare facilities.
Mould
Mould refers to a diverse group of fungi that can be found both indoors and outdoors. Moisture and warm temperature can promote the growth of mould indoors.
Mould can be found in poorly ventilated areas such as
- bathrooms,
- areas with water leaks,
- behind drywall with moisture build-up, and
- on windows with condensation.
Controlling the sources of moisture and ensuring adequate ventilation is key in preventing mould growth. It can become a problem for individuals who are sensitive to mould as inhalation or direct contact with mould spores can trigger allergic reactions. Those with compromised immune systems or underlying respiratory conditions may experience more severe reactions.
By implementing appropriate measures, mould prevention or management can be applied to promote healthy indoor environments. There are many practical strategies such as effective moisture control, proper ventilation and regular maintenance in mould prevention.
Learn more on the step-by-step guidance when you encounter mould growth in your indoor space and when to seek professional assistance and how to prevent mould recurrence.
