Implications of Soil Clay Minerals on the Availability and Speciation of Inorganic Arsenic in Soil-crop Pathways in selected Arsenic Affected Soils of West Bengal

Four surface soil samples three from arsenic (As)-affected soils, and one from the unaffected area of West Bengal were collected. The physical and chemical properties of the soils revealed contrasting characters. The mineralogical characterization of the corresponding clay minerals in these soils suggested the dominance of illite and kaolinite minerals. These minerals are responsible for greater As adsorption, especially the As (V) form compared to As (III). In plant body, however, As (III) predominates over As (V) though the ratio depends on the soil moisture condition. In general, there is considerable build-up of As from the Ascontaminated groundwater, used as the irrigation source, to soil-plant system.