Investigation the origin of Arsenic contamination in soil and agricultural products of Hashtrood city, East Azarbaijan Province

Arsenic concentrations in soil and water can be increased by natural processes such as sedimentation of volcanic ash, mining, geothermal debris, oxidation and dissolution of minerals. Also, application of herbicides and animal fertilizers in agriculture can increase the concentration of arsenic in the environment. In the Hashtrood area of East Azarbaijan province, evidence of arsenic contamination has been reported, possibly due to arsenic contaminated water, soil and crops. The purpose of this study was to identify the amount of pollution of water resources, soil and crops in the region to arsenic

Sampling of surface water resources, soil, and plants cultivated in the area in four seasons and the concentration of arsenic was determined in samples.

Analysis of water samples showed the average concentration of arsenic 0.341 mg/lit. The mean concentration of arsenic in the soil in the area is 127.95 mg/kg. The concentration of arsenic is less than permissible 1mg/kg in agricultural products in both regions.

Theresults of the comparison samples with standard values represent water and soil arsenic contamination in this area which in the most samples is higher than the standard. The low concentration of arsenic in the plants in the area can be due to the alkalinity of the soil and high clay content. Arsenic has a low solubility in this type of soil and is absorbed on soil clay particles and plants grown on these soils cannot easy to absorb arsenic from the soil.