Heavy Metal Contamination and Distribution in the Parks City of Islam Shahr, SW Tehran, Iran

ABSTRACT

Islam Shahr is relatively small city in the south of Tehran (10km), Iran. It is located within the Recent Alluvium Formation of Tehran alluvial. This formation is associated with heterogeneous to poorly sorted clays and silts. The overall objective of this study was to better understand the nature of soil contamination in this area. Such information should be useful for enhancing safe parks city in the Islam Shahr urban area while minimizing adverse effects of soil contamination on human health.

In this research, 25 soil samples were analyzed by ICP for Al, Co, Cr, Cu, Pb, Zn, Ag, Cd, Hg, As, Se. The concentration of Ag, Cd, Hg, As, Se was less than detection limit. Since early work on soil geochemistry of Islam Shahr is not available, the elemental compositions of these soils were normalized using average upper continental crust values. Data processing shows the average concentrations of Cu, Cr, Co, Pb and Zn were higher than the upper continental crust background levels. Also, when the Chinese National Soil Standard values were used as a reference, Co, Cr, Cu, Pb and Zn contaminations in the city park soils of Islam Shahr were similar to Grade I of contamination. Most of the contaminated sites are located in the Vavan areas, where urbanization, heavy traffic, agricultural and industrial activities are high, but it does not pose an immediate threat to the environment. The Islam Shahr is new developed city during the 15 years ago, thus such contaminations are so high and to be worrying for this short period.

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