evaluation of some heavy metals contamination around urmia lake and city by soil pollution indicators

The present study aims to assess the spatial distribution of heavy metals in sediment of the western bed of urmia lake and around soil by using pollution indicators. for this aim, twenty soil and surface sediment samples (0-20 cm) were collected, and metals concentration was determined by inductively coupled plasma optical emission spectroscopy. the average total concentration of nickel, manganese, cadmium, chromium, boron, and bismuth are 19.97, 163.56, 0.39, 14.68, 68.38, and 0.76 mg kg-1 respectively. the geo accumulation index for nickel, manganese, chromium, cadmium, and boron are in the non-polluted category and bismuth is in the non-polluted category for moderate pollution. investigation of the enrichment factor shows that the manganese is moderate to severe; nickel, chromium, and boron are severe, and cadmium and bismuth, are at an enormous enrichment level. calculation of contamination factors in the region indicates that cadmium, boron, and bismuth are in the middle pollution category. the result of pearson correlation coefficient analysis shows that the calcium carbonate content of the soil with all metals has a negative correlation, and would reduce mobility and decrease the pollution of metals. the results of this study indicate that the total concentration of the boron in the sediments of the urmia lake bed is significantly higher than the average of the crust. also, cadmium concentration in agricultural land is higher than the average in the earth’s crust, and controlling actions should be implemented to reduce the use of chemical fertilizers as a factor in increasing the concentration of cadmium.