* Corresponding author: mmohammadi@pgu.ac.ir 1 Volume 1, No.1, September 2013, Pages 1-12 Assessment of Heavy Metal Contamination in Topsoil of Northern Coasts of Persian Gulf Fatemeh Valizadeh-kakhki 1, 2 , Mohammad Pauzi Zakaria 2 , Mehdi Mohammadi 1,* , Hassan Tajik 3 , Elaheh Valizadeh-kakhki 4 1 Persian Gulf Research Institute, Persian Gulf University Bushehr, Iran 2 Faculty of Environmental Studies, University Putra Malaysia, Malaysia 3 Faculty of Science, Gilan University, Gilan, Iran 4 Islamic Azad University of Mashhad, Mashhad, Iran ARTICLE INFO ABSTRACT Received July 18, 2013 Accepted August 29, 2013 Persian Gulf and its coastal areas are the world's largest source of crude oil and related industries govern the region. One of the contaminants in this area is heavy metals associated with oil spill. More importantly, vanadium, nickel and zinc can be named in this regard. In this study, the contamination of northern coasts of Persian Gulf is selected to investigate for trace metals of V, Ni, Cd, Co, Zn, Cu, and Pb pollution in soils, their distribution and levels of contamination. The study was carried out on the northern coasts of Persian Gulf including three provinces of Bushehr, Khuzestan and Hormozgan. The results revealed a great increase in the amount of vanadium in most of the sampling sites to be higher than background values for soil. In Southern Pars Gas Field there was the concentration of 7713.77 mg Kg -1 . The concentration of other metals was almost high and a great relationship between vanadium, zinc, cadmium, and lead was found. Keywords heavy metals Persian Gulf topsoil contamination vanadium nickel 1 INTRODUCTION Persian Gulf and its coastal areas are the world's largest single source of crude oil and related industries govern the region. Safaniya Oil Field, the world's largest offshore oil field, is located in the Persian Gulf. Persian Gulf with its own geographical and ecological characteristics of marine ecosystems is among the rarest marine ecosystem in the world. It is well-known as a great economic resource of oil and gas and two-third of the world oil resources are located there. Each year, around 25000 oil and non-oil tankers have traffic in it, so it is one of the world's busiest waterways for oil and non-oil tankers (Metz,1993). About 50 percent of the pollution of the Persian Gulf is caused by non-oil pollutants and the remaining 50 percent is due to oil sources. Most of the oil discharged in the environment originates from natural sources and fuel oil consumption. However, the number of accidental spills has highly