Abstract

The long-term trends and spatial variability of PM2.5 and PMio over the period between 2000 and 2012 in the Santiago Metropolitan Area, Chile are studied. The annual PMio and PM2.5 mass concentration ranged between 76 5 and 52 41.ig [T1-3 and between 32 4 and 24 3, respectively. The large levels of PM observed during the cool season (April September) compared to the warm season (October March) can be explained by meteorological conditions and increased emissions. PM2,5 represents approximately 45% 5% and 60% 10% of PM10 in the warm and cold seasons, respectively. Reductions in PMio and PM2.5 were observed in the ranges of 2.46 to 0.31 and 3.17 to 1.80% yearl, respectively. For the city, the comprehensive air pollution level declined gradually, illustrating that the air quality improved over the last decade. However, the air quality standards were still being exceeded, indicating the need to update and strengthen the policies to control PM pollution. (C) 2014 Elsevier Ltd. All rights reserved.