The Study on the Level of Pollution and Spatial Distribution of Concentrations of Heavy Metals (Cr, Ni, Cu, Pb and Zn) in the Industrial City of Mah-Shahr

Due to their toxicity and persistence in the environment Heavy metals are one of the most significant soil contaminants. So, it is essential to investigate the distribution of heavy metal for controlling contamination of soil and maintaining the quality of the environment. This study aimed to assess the level of contamination and mapping the spatial patterns of heavy metals like chromium, nickel, copper, lead and zinc in topsoil was performed in Mahshahr in 2016. For this purpose, by the use of systematic sampling method 51 surface soil samples (0-20 cm) were gathered and concentration of these metals was measured by XRF. Also, soil properties such as: EC, pH, lime and soil texture was identified. Pollution index (PI), and Nemerow integrated pollution index (NIPI) was used to determine the soil contamination. Concentration Distribution maps of heavy metals was prepared using the interpolation method in geographic information system (GIS). Principal component analysis (PCA) was performed to investigate the relationship between metals. The results indicated the highest PI of chrome and nickel which are in high contamination level. Many urban soils in Mahshahr have been contaminated with a sort of low or moderate levels of lead, zinc and copper. NIPI showed that all parts are in high pollution levels. The results of principal component analysis indicated that copper, lead, and zinc metals were placed under the same category revealed to be of man-made and common origins. Chromium and nickel have been placed in a separate category and the quantity of pollution index of these metals with high variable coefficient was determined to be of anthropogenic origin.