The mobility of arsenic from highly polluted farmlands to wheat: Soil-Plant transfer model and health risk assessment

Arsenic (As) can be transferred from soil and accumulated in food plants. So far, we have a knowledge gap about transference of As from agricultural soils to wheat plant in the natural polluted environment. The aim of present study was to investigate As transfer from soil to different tissues of wheat at a highly As polluted area. In this regard, the mobility indices were used to explain As transfer and accumulation from soil to wheat plant. Moreover, the relationships between soil properties including soil As content, pH, cation-exchange capacity (CEC), electrical conductivity (EC), organic matter (OM), Fe, and Al percentage with As concentrations in wheat root, straw, and grain were investigated. Finally, the potential health risks of As exposure to humans through consumption of the local wheat crops were assessed. According to the results, harmful degree of As was accumulated in different parts of wheat plant. The impact of different soil properties on As accumulation in wheat was found to be as follows: soil As content > Al% > Fe% > OM > pH > CEC > EC. High carcinogenic and noncarcinogenic risks in all age groups of consumers were found. The minimum and maximum values for target hazard quotient and excess lifetime cancer risk were found to be 1.22, 102.97 and 0.000061, 0.33, respectively. These findings strongly support the notion that As can be entered to food chain through agricultural products cultivated in polluted soils.