Inhaled and inspired particulates in Metropolitan Santiago Chile exceed air quality standards

• PM concentrations were analyzed over the 2000–2012 period in Santiago, Chile.
• Comprehensive air pollution level declined gradually, in the last decade.
• The PM2.5 represents over 45% of the PM10.
• The national standards and WHO guideline are exceeded over the all period.
• Its necessary updates and strengthens the policies and strategies for control.

The long-term trends and spatial variability of PM2.5 and PM10 over the period between 2000 and 2012 in the Santiago Metropolitan Area, Chile are studied. The annual PM10 and PM2.5 mass concentration ranged between 76 ± 5 and 52 ± 4 μg m−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 PM10 and PM2.5 were observed in the ranges of −2.46 to 0.31 and −3.17 to −1.80% year−1, 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.