Air quality describes the level of air pollutants in a certain area. Air pollutants can become dangerous to human health if people are sensitive to elevated levels of pollutants or are exposed to them for extended periods. To reduce risks, people need to know when pollutants are present and in what concentrations.
Environment Canada scientists assess air quality by collecting and analyzing samples taken from near ground level. Pollutant levels are affected by such factors as emissions sources, weather conditions and topography. Building on their expertise in weather prediction, Environment Canada scientists have developed complex computer models that now provide air quality forecasts for major centres in Canada.
Courtesy Environment Canada