Investigation of major heavy metal concentration in urban runoff (case study: North and east catchment of Tehran city)

Urban runoff as one of the most important emission sources of heavy metal to the environment has potential environmental and health risks. This study aimed to evaluate the content of ten heavy metals in runoff of Sorkheh Hesar catchment, Tehran for this purpose, Runoff samples were taken from the outlet of Sorkheh Hesar catchment during three flood events in 2018- 19 and the total concentration of heavy metals was determined by ICP-MS. Fe, Mn, Zn, Pb, Cu, Cr, Ni, As, Mo and Cd had the highest abundance in all samples, respectively. The results of Spearman's rank correlation coefficient showed strong correlation between most metals, especially Fe, Mn, Zn, Pb, Ni, Cd and Cu, which indicating the same input sources and similar geochemical behavior. Also the mean values of Contamination Index, Heavy Metal Evaluation Index and Heavy Metal Pollution Index were 24.7, 30.1 and 130.2, respectively which indicated most of the samples were in contaminated and high contaminated level, due to high concentration of three elements including Fe, Mn and Pb in compare to standard permissible values.