摘要：Since particulate matter (total suspended particles and particulate matter with median aerodynamic diameter less than 10 m#m) is one of the important pollutants in the ambient air of Tehran, the capital of Iran, organic substances, inorganic substances and lead levels in TSP and PM__10, correlation between TSP and PM__10 concentrations, ratio among the two fractions and relation between TSP and PM__10 concentrations with meteorological parameters (relative humidity and temperature) were studied. Twenty-four hour simultaneous sampling of TSP and PM__10 has been carried out during the period of 22 December 2001 to 20 April 2002 in the ambient air of Shariati Hospital district. The results showed that inorganic substances were the most abundant component of TSP and PM__10 (Approximately 76% and 68%, respectively); 0.21 % of total mass for TSP and 0.26% of total mass for PM__10 were lead particles; 64% of lead particles had a diameter less than 10 m#m; 48% of TSP had a diameter less than 10 m#m; while atmosphere relative humidity and temperature were in the range of 50% and 5-10°C respectively, specially on Saturdays in winter and more importantly in inversion conditions, the highest concentrations of TSP and PM__10 would be expected.
