Understanding the relationship between Outdoor and Indoor Air Quality

Indoor Air Quality (IAQ) is your strongest weapon against its effects on your health. Indoor air pollution, the degradation of indoor air quality by harmful chemicals and other materials, can be up to 10 times worse than outdoor air pollution. This is because confined places allow potential pollutants to build up more than open spaces do. Outdoor pollutants can build up in the lower atmosphere due to temperature inversions, which happen during periods of cold weather when warm air rises into the upper atmosphere and traps cold air beneath it, causing pollutants to build up at low altitudes. Results indicate that indoor pollutant concentrations may be up to 80% of the concentration outdoors but can greatly exceed outdoor concentrations.

Additionally, it has been shown in studies that indoor pollutants usually follow outdoor pollutant trends with only a small time delay due to mixing and dilution factors in the environment. The interaction between indoor and outdoor air is always a topic discussed especially concerning ventilation and pollutant sources. Concentrations of pollutants indoor may also rise quickly in the mornings during rush hour traffic. outdoor air pollutants infiltrate your indoor air in ways that may not be immediately obvious.

The air pollutants from outdoor can penetrate the indoor environment and can either be diluted or accumulated according to the ventilation condition. 

A comparison between actual and modeled carbon dioxide levels indoors may provide a useful indicator of ventilation. But, ventilation often brings in fresh outdoor air to dilute indoor pollutants, but can also introduce more pollutants into your indoor air from the polluted outdoor air.

Both the outdoor and indoor pollutant concentrations are the variable of indoor pollutant concentration.