The study of TSP and PM10 concentration and their heavy metal content in central area of Tehran, Iran

Atmospheric particulate matter may exert serious health hazards because of its chemical characteristics. The main objective of this study is to assess the concentrations of total suspended particles (TSP), particulate matter (PM) with an aerodynamic diameter <= 10 mu m (PM10), and air-transmitted particulate trace metals in Tehran University (a central location in Tehran, capital of Iran) ambient air, for the period of 5 months viz. February-June 2007. Furthermore, the present work examines the daily levels of fine particles in comparison with the proposed limiting values from the U. S. Environmental Protection Agency (65 mu g m(-3) for PM10). The sampling for TSP and PM10 was performed using a high-volume sampler. The TSP and PM10 levels were determined by gravimetry and the metals by flame atomic absorption spectrometry. Arithmetic means of 151 +/- 44 mu g m(-3) and 90 +/- 38 mu g m(-3) were determined for TSP and PM10, respectively. Comparing with EPA primary and secondary air quality standards, only PM10 concentrations in 3 days were higher than the standard values. Heavy metal content of both TSP and PM10, such as chromium (Cr), cadmium (Cd), and lead (Pb), were also analyzed separately during the same period using atomic absorption spectrometry. The average concentrations of heavy metal in TSP were Pb: 183.63 +/- 147.81 ng m(-3); Cr: 13.72 +/- 2.40 ng m(-3); and Cd: 6.80 +/- 1.97 ng m(-3) and for PM10 were: 150.36 +/- 157.01 ng m(-3); Cr: 9.12 +/- 2.14 ng m(-3) and Cd: 6.87 +/- 2.22 ng m(-3).