Urban Air Quality SOE Bulletin No.
Many Canadian cities continue to experience unacceptable air quality, especially in summer.
The most frequent causes are ground-level ozone and airborne particles, which, combined with other air pollutants, produce a condition known as smog . Urban air also contains trace amounts of many toxic chemicals, including various volatile hydrocarbons, such as benzene. Air pollution can have significant effects on human health, ranging from eye, nose, and throat irritation to reduction of lung capacity, aggravation of respiratory diseases, and even premature death. In fact, recent studies have shown that hospital admissions increase with increasing air pollution, even at pollution levels regularly experienced by Canadians. These studies further suggest that there may be no safe levels of exposure to certain air pollutants, including inhalable airborne particles and ground-level ozone.