Multivariate statistical approach to identify metal contamination sources in agricultural soils around Pb–Zn mining area, Isfahan province, Iran

The aims of this study are to evaluate the extent of toxic metal pollution in agricultural soils near the Pb–Zn mining area (Irankuh mining area, Isfahan province, Iran), and to find out their origins. A total of 32 agricultural topsoil samples were collected from the area under study and then, the concentration of toxic metals including Pb, Zn, Ni, Cu and Cd were determined by using atomic absorption spectrophotometry. The results showed that the mean concentrations of Pb, Zn, Ni, Cu and Cd were 51.80, 60.34, 35.75, 12.05 and 1.38 mg/kg, respectively. Various multivariate analysis including correlation coefficient analysis, factor analysis and cluster analysis were used to analyze the analytical data as well as to identify the possible pollution sources of toxic metals. According to the factor analysis and cluster analysis, 5 toxic metals were classified into three groups. The first group includes Cu, Zn and Pb; the second group includes Ni, and the last group includes Cd. To understand the current environmental status, the geo-accumulation index (Igeo) evaluation were applied. The average value of Igeo for Ni, Zn, Cu, Pb and Cd in the soil samples were obtained to be 0.23, 0.80, 0.96, 1.60, and 4.62, respectively. The results shows that the agricultural soil samples were moderately polluted with respect to Zn, Cu and Ni, moderately to strongly polluted with respect to Pb, and heavily to extremely polluted with respect to Cd.The aims of this study are to evaluate the extent of toxic metal pollution in agricultural soils near the Pb–Zn mining area (Irankuh mining area, Isfahan province, Iran), and to find out their origins. A total of 32 agricultural topsoil samples were collected from the area under study and then, the concentration of toxic metals including Pb, Zn, Ni, Cu and Cd were determined by using atomic absorption spectrophotometry. The results showed that the mean concentrations of Pb, Zn, Ni, Cu and Cd were 51.80, 60.34, 35.75, 12.05 and 1.38 mg/kg, respectively. Various multivariate analysis including correlation coefficient analysis, factor analysis and cluster analysis were used to analyze the analytical data as well as to identify the possible pollution sources of toxic metals. According to the factor analysis and cluster analysis, 5 toxic metals were classified into three groups. The first group includes Cu, Zn and Pb; the second group includes Ni, and the last group includes Cd. To understand the current environmental status, the geo-accumulation index (Igeo) evaluation were applied. The average value of Igeo for Ni, Zn, Cu, Pb and Cd in the soil samples were obtained to be 0.23, 0.80, 0.96, 1.60, and 4.62, respectively. The results shows that the agricultural soil samples were moderately polluted with respect to Zn, Cu and Ni, moderately to strongly polluted with respect to Pb, and heavily to extremely polluted with respect to Cd