PM_(10) and PM_(2.5) Concentrations and Trends at Canadian Urban and Rural Sites

摘要

Despite the fact that national air quality objectives for PM_(10) and PM_(2.5) are still in the development stage in Canada, there exists an extensive federal-provincial monitoring effort for particulate matter (PM) in ambient air. As of the fall of 1997, 72 manual and 43 continuous PM_(10) monitoring sites were in operation and 19 manual and 34 continuous PM_(2.5) instruments were in the field. Up to twelve years of measurements of PM_(10), PM_(2.5), SO_4~(2-) and other trace elements are available for 19 Canadian locations. The highest mean and 90~(th) percentile PM~10) concentrations greater than the proposed national air quality objective of 40 mug/m~3. The highest mean and 90~(th) percentile PM_(2.5) concentrations were recorded at sites in the Windsor-Toronto corridor and at a roadisde site in Montreal. The lowest mean and 90~(th) percentile concentrations were recorded at the rural sites of Kejimkujik and Mount Sutton.