Bioavailability, distribution and health risk assessment of arsenic and heavy metals (HMs) in agricultural soils of Kermanshah Province, west of Iran

Kermanshah Province as an agricultural hub exports food crops to neighboring countries. In this study, contamination status, bioavailability, spatial distribution, and ecological and human health risk of arsenic and heavy metals (HMs) in soil were investigate. For this purpose, 121 agricultural soil samples were collected and analyzed using ICP-MS. The data were studied by calculating some geochemical indices, and using geographical information system and statistical analysis. Results showed that Cd has the highest bioavailability, following by Cu and As. Also, Cu was severely associated with organic matter. Enrichment factor (EF) followed the order of As > Cu > Pb > Se > Cd > Zn > Ni > Cr, and the soil pollution index (SPI) ranged from 0.82 to 2.65. Low potential ecological risk was measured for most of the samples. However, Kermanshah County and Eastern parts of the Province showed the highest HMs enrichment and ecological risk. Moreover, high carcinogenic risk of Cr and Ni threatens the children. Cr showed also high non-carcinogenic hazard index (HI) for children. Principal component analysis (PCA) indicated the anthropogenic origins for As, Cd, Cu, Pb, Se and Zn, while Cr and Ni originated mainly from a geogenic source. Furthermore, Kruskal-Wallis H test revealed that As, Cd, Cr, Cu, Ni, Pb, Se and Zn concentrations were significantly different (p < 0.05) between 16 Counties of the Kermanshah Province. Overall, the management of urban and industrial contamination sources is required to minimize the concentration of bioavailable portion of HMs and preventing residents of the area from being exposed to contaminants.