Bioavailability and speciation of arsenic in urban street dusts from Baoding city,China

Twenty-one street dust samples were collected from the urban sites in Baoding, China, to investigate the species and bioavailabilty of arsenic in them. The ecological risk and bioavailability of arsenic were evaluated using three models including Bioavailability Factor (BF), Contamination Factors (C_f)and Geoaccumulation Index model (I_geo). The species of arsenic in the dust samples were analyzed using an optimized BCR sequential extraction method. The total concentrations of As in the street dust samples ranged from 13.16 mg kg^?1 to 67.26 mg kg^?1. Geoaccumulation index (I_geo) of As ranged from 0.28 to 1.99. The speciation analysis indicated that As in the street dust samples were mainly in the residual fraction (F4), and the proportion ranged from 84.35% to 87.07%. Moreover, the ranges of the BF and C_f were 0.650–0.129 and 0.119–0.186, respectively. The results indicated that arsenic contained in the street dust samples was with low bioavailability.