Accumulation and interaction of fluoride and cadmium in the soil-wheat plant system from the wastewater irrigated soil of an oasis region in northwest China

Abstract

Contamination of agricultural soil with high concentrations of fluorine (F) and cadmium (Cd) have raised significant concerns regarding their impacts on human health but the relationship between F and Cd in soil-wheat plant system in an oasis region has not been investigated. This paper aims to study the accumulation and interaction of F and total Cd in the soil-wheat plant system while considering the potential risks of F and Cd to human health. Soil samples were collected from wastewater-irrigated oasis regions, Dongdagou and Xidagou. The concentrations of total F (FT) and Cd in soils from the Dongdagou and Xidagou stream basins were higher than those in uncontaminated soils (F=270.25mgkg−1, Cd=0.10mgkg−1). Water-soluble F (FW) and FT contributed to F concentrations in underground parts of wheat when the samples were collected from Dongdagou, however, F in aboveground parts may be mainly influenced by atmospheric F. The main source of F in wheat plants collected from the Xidagou site may be mainly controlled by atmospheric F, including aboveground and underground parts. Soils in the studied region pose a potentially severe health risk for humans via bioaccumulation of toxic metals through the food chain, and therefore, are not suitable for planting wheat meant for human consumption. Cd had a significantly negative effect on F accumulation in wheat root from Dongdagou (P<0.01). This field study provided F-Cd interactions that occur in soils from an oasis region at environmentally relevant concentrations.