Geostatistical assessment of Pb and the related soil physical and chemical properties in near-surface soil around Sepahanshahr, Isfahan

This paper presents a survey on soil Pb concentration around Sepahanshahr town located in vicinity of Isfahan. Due to the lack of regulation and environmental education and awareness, Sepahanshahr is now a rapid growing residential area suffering from the considerable consequences of poorly regulated mining activities operating in its vicinity. The aim of this study is to explore the spatial structure of Pb distribution and to map Pb pollution using geostatistical techniques. 100 near-surface soil samples were collected and analyzed for Pb and some other related soil physical and chemical variables such as pH, organic matter content, electrical conductivity, clay, silt and sand contents. The variography results show a strong spatial dependency in Pb data due to the dilution effects of natural factors including atmospheric dispersion and precipitation. The almost same range values calculated for both Ln-transformed Pb data and sand content suggest presence of co-regionalization. Kriged Pb map shows a strong gradient of Pb concentration around the three mining sites activating in the area. The results of this study provide insight into identification of the extent and the spatial variability of Pb pollution in the mining sites and surrounding area.