Evaluation of source and biological accessibility of heavy metals in the soil of Tehran northwestern elevations

Subject Areas : environmental management

Abdolreza Karbasi ¹ , Gholamreza Nabii Bidhendi ² , Faramarz Moattar ³ , Zohreh Barzegari ⁴

1 - Faculty of Environment, University of Tehran
2 - Faculty of Environment, University of Tehran
3 - Faculty of Environment and Energy, Science and Research Campus ,Azad University of Tehran
4 - Faculty of Environment and Energy, Science and Research Branch, Islamic Azad University

Received: 2007-06-06 Accepted : 2007-08-07 Published : 2009-09-23

Keywords: Soil pollution, Heavy metal, biological accessibility, cluster analysis,

Abstract :

Soil can retain the environmental pollution, so by chemically analyzing it, we can learn about the pollution of a region. In the present study, samples of Tehran northwest soil are used. In total, 16 soil samples are collected and the mean concentration of Pb, Zn, Ni, and V are computed to be 173ppm, 101 ppm, 62 ppm, and 44 ppm, respectively. The results show a higher concentration of Pb than those of other elements. Moreover, the mean Pb concentration in the present study is 1,200% higher than that of the earth’s crust, which is because of air pollution. The elements (Pb, Zn, Ni, V, & Fe) were also studied in terms of biological accessibility and the related figures were obtained in the following order: Pb(929ppm)>Zn(27ppm) > Fe(7ppm) > Ni(5ppm) > V(0ppm) Furthermore, the cluster analysis revealed that Pb had an organic basis and that there was a high positive relationship between Ni and V. Since V is known as an oil pollution indicator, it can be concluded that Ni is scattered in the soil of the region due to fuel consumption.