Application of pollution indices to investigate of heavy metals ‏sequestration in soil (Case Study of Nahavand Cement Factory)‎

The cement production process is a major source of heavy metal contamination through dust emissions due to massive use of minerals and fossil fuels in this industry. The purpose of this study was to investigate the effect of distance from the source (Electrophilter) on the amount of heavy metals in the surrounding soils of Nahavand cement factory. Soil samples were collected at 300, 500, 800, 1000 and 2000 meter from the cement factory and also Electrophilter dust were sampled.At these intervals, 4, 4, 3, 4 and 2 points with three replicates were sampled, respectively. Also, 6 samples were collected 11 km from the factory as control area. Samples were prepared, digested and then the concentration of heavy metals was measured by atomic absorption spectrometry. According to the results, there was a significant difference (p<0.05) in the heavy metals concentration (Cd, Pb, Zn, Cr and Mn) between different distances and Electrophilter.The highest values of the pollution indices were observed at the distance of 300 meter and pollution decreased along with increasing distance from the cement factory. Meanwhile, the heavy metal concentrations in the control area were less than their concentration around the cement factory. The highest values of contamination factor (CF) and Igeo index were determined for cadmium, lead and nickel. The results of principal component analysis showed that the first component include Cd, Mn, and Pb and the second component include Zn, Ni, and Cr. Regarding to the, statistically significant difference between the distances, and higher concentrations around the cement factory than the control area, it can be concluded that Nahavand cement factory is the main source of heavy metals pollution in its surrounding soils.