A pollution index for agricultural soils

The main purpose of the present investigation was to develop a pollution index for agricultural soils. For this purpose, 58 soil samples were collected from agricultural lands in Hamedan Province (Iran). The elemental contents of As, Cd and Co in soil samples and agricultural crops were measured by atomic absorption spectroscopy. The spatial distribution of studied metals was prepared by Kriging method. It is concluded that agricultural activities have led to the higher concentrations of Co, Cd and As. Results of the chemical partitioning studies revealed that a considerable portions of As, Cd and Co in agricultural soils are derived from anthropogenic sources. We believe that pollution index should show values that are in accordance with chemical partitioning data. The newly developed pollution index showed slightly higher values when compared with the previously published indices such as geochemical index (I-geo) and pollution index (I-poll). The health risk index in the area of study was found to be lower than many other reported ones. Among the studied elements, Co has the highest transfer factor of 17.95 that could be attributed to its lower retention rate.