Spatial variation of lead and cadmium concentration in surface soil of parts of central Iran (Case study: Qom plain)

The aim of this study was to prepare a map of the distribution of lead and cadmium in the topsoils of parts of Qom province to the center of Qom city, with different agricultural, urban and industrial uses of barren in two total and absorbable forms. The spatial distribution of these elements in surface soils with different uses with an area of ​​1054 square kilometers was investigated. Sampling was performed at 209 points by networking the study area and the total and absorbable amount of lead and cadmium was determined using an atomic absorption spectrometer. All-round variograms of these elements were drawn by Variowin software. Due to the lack of a proper structure, no changes were made to the cadmium, kriging and mapping. Intermediation was performed by point kriging method with WinGslib software. MEE and MSEE were used to determine the accuracy of the estimates. The range of changes in total lead with a minimum of 9.6 and a maximum of 123.4 mg / kg is reported to be 113.8. In this study, the minimum and maximum total cadmium concentrations were 0.2 and 5.5, respectively. The average concentration of absorbable lead in the study area is 4.1 mg / kg with a minimum of 0.5 and a maximum of 34.8 mg / kg. Based on the lead distribution maps, it seems that the effective factor on the increasing trend of this element is the type of use. Lands with urban and industrial use had the highest amount of total and absorbable lead, which indicates the high potential of the area for pollution. Therefore, it is necessary to take the necessary management measures to prevent the occurrence of destructive environmental accidents.