In October 2020, the Government of Canada “Causes of Poor Indoor Air Quality” was published.
The causes of poor indoor air quality can usually be traced to indoor activities and sources such as dampness, and poor ventilation. Poor indoor air quality can affect your health and should be resolved. Poor indoor air quality is affected by the level of ventilation in a building. Ventilation is designed to remove indoor air and supply fresh outdoor air, reducing indoor pollutants and limiting indoor moisture contributing to mould growth.
The amount of fresh air entering the building from outside and how effectively contaminated air is being exhausted from the house will have an impact on indoor air quality.
During periods with high levels of outdoor air pollution, reduce air entering the home from outside.
Read the Reference: https://www.canada.ca/en/health-canada/services/air-quality/causes-poor-indoor-air-quality.html