The role of Mineral Salts Company in pollution of Mighan playa sediments with heavy metals by contamination indices and multivariate analysis methods, Arak, Iran

Heavy metal concentrations were investigated for 30 sediments collected from different regions of Mighan playa/lake. The means of Cr, Cu, Ni, Pb, Zn, and Cd in sediments of playa/lake were much lower than the soil guideline values of Iran and background values of the region (BVR). However, the maximum concentrations of Cr, Cu, Ni, Pb, Zn, and Cd were higher than BVR. Only 7% of Cr, Cu, Zn, 27% of Ni, 14% of Pb, and 38% of Cd concentration exceeded the BVR. The heavy metal Cr, Zn, Ni, and Cd are the most important metals in different land use. About 11% of the samples in the lake land use contain Cr, Ni, Pb, and Zn have concentrations higher than BVR. The concentration of Cu and Pb in 33% and 67% samples is exceeded the BVR in the tail of Mineral Salts Company. The spatial distribution patterns of Cr, Cu, Ni, Pb, Zn, and Cd were generally similar and increase from Mighan playa/lake to the Arak city and mainly affected by anthropogenic sources. Among the six types of land use, the concentrations of Cr, Ni, Zn, and Cd in the rangeland and wastewater sludge were significantly higher than those in the other land use (p<0.05). In factor analysis, Cr, Ni, Zn in factor1, Cd in factor2, Pb, Zn in factor3 were originated from the municipal sewage, industrial plants activities, and Arak urban traffic.