Difference of trace element exposed routes and their health risks between agriculture and pastoral areas in Bay County Xinjiang, China

Abstract

The concentration level related to toxicities of trace elements in drinking water, rice, wheat flour, and their associated negative impacts on human health have become an emergent issue in China. Because Xinjiang is the largest province in China with the majority of arable pasture landavailable for cultivation, it is important to analyse the concentrations of trace elements in relation to their toxicities in water, rice, and wheat flour and to investigate the health risk differences between agricultual and pastoral areas in Bay County, Xinjiang.The study results showed that (1) metal concentrations from drinking water, rice, and wheat flour were within the permissible limits; (2) concentration levels of trace elements and their total risk from drinking water and rice were higher in the agricultural areas than those in the pastoral areas, whereas concentration levels of trace elements and their total risk from wheat flour were higher in the pastoral areas than those in the agricultural areas; (3) the concentration level of the trace elements in rice were higher than in the wheat flour, but the risk from the wheat flour was higher than the risk from rice; (4) total non-cancer risk from the flour (HIf) in both areas exceeded the respective safe reference doses; (5) total cancer risk from the wheat flour, rice, and water exceeded the safety limit (1 × 10−4); (6) for the exposed population, arsenic was suggested as the most evident pollutant leading to carcinogenic concernsregarding the water, rice, and wheat flour; (7) the risk index from the wheat flour made up the highest percentage both in the total cancer risk and the non-cancer risk, followed by rice and then water; and (8) the human health risk was attributed to influence from the local environment in the agriculture areas, while it was attributed to the external environment in the pastoral areas.

Variability in plant trace element uptake across different crops, soil contamination levels and soil properties in the Xinjiang Uygur Autonomous Region of northwest China

“…One-way ANOVA results showed that the contents of seven trace elements were significantly different among three farmland soils except Ni (Table 1 and supporting information Table S5 ). This may be due to the multifactor functioning such as pollution source and the interaction between plants and soil 1 , 3 , 20 . For example, Zhu et al 45 , has shown that variance in plant accumulation capacity may cause variability of soil trace element content among different farmlands.…”

“…Large diesel- or gasoline-powered dispensers were used to harvest crops and spray pesticides. In these process, Hg and Zn from farm machinery tyres were likely added to soil 1 , 20 . Cr may have accumulated through the atmospheric settlement and irrigation 14 , 48 .…”

“…2 ). These differences may be attributed to different crop environmental adaptability and their capacity of element-enrichment 20 , 21 , 51 . For example, grain is known for having larger enrichment coefficient for Cr, Hg and Zn, whereas vegetables having a higher capacity for enrichment for Cd and Pb (Supporting information Fig.…”

“…Health risk assessment of crop ingestion. The dietary consumption of crops containing trace elements is considered as the major source of hazardous element exposure in humans 10,20,33 . The average daily dose (ADD) (mg kg −1 day −1 ) of trace element via dietary consumption was assessed based on the U.S.…”

“…As the majority of trace elements in crops are absorbed from soil via root uptake 14 , 16 , variations in agricultural activities may cause the difference in the contamination status and potential health risks of trace elements among different crops 3 , 15 , 17 . While trace element contamination in crops is more harmful to human health than that in soils 18 , 19 , the current research focus has been mainly on the influences of agricultural activities on the soil trace element contamination and the potential risks of different farmlands 1 , 11 , 13 , 20 , with very limited data relating to the edible parts of crops and the potential risks for human exposure 10 , 18 , 21 .…”