The air surrounding us on the land and in our communities is called “ambient” air. It contains mostly nitrogen and oxygen, with a small amount of carbon dioxide and water vapour. It also contains trace amounts of contaminants such as gaseous chemicals and particulate matter (dust).
Research has linked the presence of air contaminants at certain concentrations to human health issues such as respiratory and cardiovascular problems as well as negative effects on property, vegetation, land and water.
The naturally occurring levels of particles and chemicals in the air are called “background levels”. Human activities and unusual natural events such as wildland fires can cause pollution and raise the levels of particles and chemicals above these background levels. Tracking levels of the most common contaminants (also known as air pollutants) provides an indication of air quality and the impacts of emissions from both industrial and community development.