CHARACTERISTICS OF INHALABLE PARTICULATE MATTER IN ALBERTA CITIES

Inhalable particulate measurements from 1984 to 1994 at Edmonton and C algary reveal similar physical and chemical properties which are compa rable to other Canadian prairie cities. Because of geographical and em ission-source differences, particulate measurements in these two Alber ta cities exhibit characteristics significantly different from those o btained in eastern North American cities. While median PM10 concentrat ion is about 25 mu g m(-3), which is approximately 63% of the total su spended particulates (TSP), PM2.5 concentration is about 40% of that o f PM10. Over the 10 years there was a decreasing trend in both size fr actions. PM2.5 shows a similar seasonal pattern in Edmonton and Calgar y, with a slightly higher concentration in winter; whereas coarse part icles are generally higher in spring at Edmonton and in winter at Calg ary. Relationships were established from co-located measurements of Du st and Smoke index (in Coefficient of Haze, COH, units) and PM10 conce ntration with a correlation coefficient of 0.51, and TSP and PM10 conc entrations with a correlation coefficient of 0.93. Sulphate is the hig hest explainable mass fraction in fine particles, while minerals contr ibute most to the coarse particles. About 80% of the total sulphur mas s is within the fine particle fraction. Seasonal variations within ind ividual chemical components are relatively less than that among chemic al components. Particles of different sizes originate from distinct so urce sectors. Seasonal variations in source contribution are detected, particularly for mineral soil and road salt. (C) 1998 Elsevier Scienc e Ltd. All rights reserved.