In order to investigate the sources and assessment the role of soil characteristics in soil contamination with arsenic, 229 soil samples from 83 profiles in different landforms and 58 surface soil samples were collected from Bijar area. Further to routine physical and chemical experiments, iron oxides and arsenic content of all soil samples were measured. By means of evaluation the potential of arsenic contamination of the studied area, spatial variability of soil arsenic was determined according to IDW approach. Statistically topsoil arsenic concentration showed significant correlations with clay content (r=0.77), sand (r=-0.45), silt (r=-0.48), CEC (r=0.65), and Fe oxides (r=0.65) at 0.01 probablity level. Subsoil arsenic concentrations also showed similar correlations with soil properties. Igneous iron rich rocks and mudstone showed significantly higher arsenic compared to the other rocks. According to the obtained results arsenic has translocated from the arsenic rich rocks (igneous iron rich rocks and mudstone) at the upper to the lower altitudes by erosion-sedimentation processes or dissolution. The maps obtained by IDW approach also confirmed the mentioned trends. The measured arsenic contents in the studied soils are hazardous for human and ecosystems and there is strong need for specific management practices.
