Status and associated human health risk of zinc accumulation in agricultural soils across China

Abstract Zinc (Zn) is not only an essential element for organisms, but it might also be an environmental pollutant. However, to date, there have not been any studies on Zn accumulation in Chinese agricultural soils at the national scale. In this study, soil Zn concentrations were obtained for soils from 277 sites with potential pollution (the “PP group”) and 1186 normal agricultural sites in China through a comprehensive literature search. Compared with the reported Zn contents of soils of other countries and regions in the world, the average concentration of Zn in soils in China (86.14 mg·kg−1) is relatively high. The total inventory of Zn in China’s agricultural soils was calculated to be 3.08 × 1010 tonnes. Zn contamination was serious in the PP group (e.g. 7076 mg·kg−1 in Yunnan province), and was primarily derived from anthropogenic activities including mining, smelting, and sewage irrigation. The accumulation of Zn in soils was influenced by different factors in different regions of China and varied with land-use pattern, with Zn concentrations in soils of different agriculture types decreasing in the following order: orchard > paddy field > vegetable land > wheat land. Zn pollution and associated risks in soils of regions in the PP group were more severe than those in normal agricultural soils. The hazard index (HI) values (for the PP group) for different human population groups varied as follows: children (2.40) > adult females (1.39) > adult males (1.23). The highest HI value obtained of 26.77 pertained to children. Overall, this study provides a comprehensive assessment of Zn accumulation in agricultural soils, and the results provide valuable information for the management and risk prevention of Zn contamination in China’s soils.