Agricultural planning by selecting food crops with low arsenic accumulation to efficiently reduce arsenic exposure to human health in an arsenic-polluted mining region

Abstract

Agricultural planning via substitution with crops of low arsenic (As) accumulation can efficiently reduce the dietary exposure from As to human health through food chain. In this study, in total 157 crop cultivars, including rice, vegetable and maize, were used and their risk of As accumulation in edible parts was studied via pot and field experiments. When soil As level was 56.7 mg kg−1, equivalent to a level of slight contamination, inorganic As (iAs) in rice grain ranged from 0.44 to 0.61 mg kg−1 Fresh weight (FW), which was 2.2–3.0 times higher than its limit in China (0.2 mg kg−1). When soil As enhanced to 156.2 mg kg−1 (moderate contamination), mater convolvulus and crown daisy had the over-limit risk of As accumulation in their edible parts. Green tender, pakchoi cabbage, rape and amaranth emerged with the over-limit risk of As, when soil As reached 238.3 mg kg−1 (severe contamination). Comparatively, maize and tuber or fruit vegetables had the lower levels of As in their edible parts and sweet potato, peanut, pepper and potato had less variation of As accumulation among cultivars of the same crop. A recommended list was provided for preferable food crops under different contamination level of As in soils. Switching paddy soil into upland soils and planting in priority with tuber or fruit vegetables and maize are encouraged. Agricultural planning resulted in significant decreases for the target hazard quotient (THQ) and target cancer risk (TCR) of iAs via dietary exposure to the residents near the realgar mine in Shimen County of China.