Heavy metals are very important from environmental consideration due to their toxicity and accumulative properties. Although these elements present generally at low concentrations in the soil, but the increase of their concentration either naturally or through human activity pose the divers problems. The heavy metals accumulate mostly in the surface soil, and thus exposure more to plant uptake and traort. The understanding of the spatial variation of heavy metals in the soil is an important precondition for monitoring and evaluating eco-environment quality in the agricultural lands. The aim of this study is the evaluation of spatial distribution of Cr, Co and Ni in the surface soil of Hamadan province, determination of the accumulation of these metals in the some crops, and assessment of health risks from heavy metals in wheat and potato. For this purpose, the surface soil samples (0-20 cm) were taken using systematic random sampling method and the concentration of heavy metals and some soil parameters such as pH, EC, the percentage of organic matter, sand, clay and silt were analyzed. The soil sampling points located on agricultural lands were determined using satellite images and potato, wheat, barely, alfalfa and corn were sampled. For interpolation and mapping the spatial distribution of heavy metals, the accuracy of Kriging methods and their models were compared by the Mean Absolute Error (MAE) values ??and Mean Bias Error (MBE), and the method with lowest error was selected. Maps of chromium and nickel distribution were prepared by ordinary Kriging with a Spherical model, and that of cobalt by disjanctive Kriging with Exponential model. The regions of the western Hamedan province had the highest concentration of chromium, cobalt and nickel. The accordance of the maps with the highest concentration and igneous and metamorphic bedrock showed that the geology is the most important factor affecting the concentration of these elements. The mean concentration of the studied elements in the province of Hamedan, except for nickel, was in the range of maximum acceptable concentration for agricultural land. Background concentrations of chromium and cobalt corresponded to the world mean. The assessment of soil contamination using Geoaccumulation Index (Igeo), based on the mean background concentration in the study area as well as the average concentration in the earth crust, dir=ltr Key words : Hamadan Province, Soil pollution, Kriging, Crops, Health risk, Heavy metals
