Trace Metal Contamination and Health Risk Assessment in Surface Waters of the Kuitun River Basin, Xinjiang, China
摘要
Water quality and safety directly impact ecosystem stability and human activity in the Kuitun River Basin, a region with early-documented arsenicosis in China. Therefore, it is important to comprehensively analyse the water quality situation in the watershed. This study investigated the distribution characteristics and health risks of 17 trace metals (K, Ca, Na, Mg, As, Cd, Cr, Cu, Fe, Li, Mn, Ni, Pb, Rb, Se, Zn, Sr) in the Kuitun River Basin, Xinjiang, China. Various evaluation indexes such as water quality index (WQI), sodium adsorption ratio (SAR), sodium percentage (Na+%) and hazard index (HI) were used to comprehensive evaluate the ecological safety of water in the basin. All trace metal concentrations met China’s drinking water and Grade I surface water standards. Correlation and PCA analysis indicated that the saline environment influenced metal transport (e.g., Pb-TDS: r = 0.668, P < 0.01). The overall water quality of the watershed was “excellent” (WQI < 50), however, there was an abnormal point in S10 which was greatly influenced by TDS. Meanwhile, Na+% evaluation of this point revealed that it was unsuitable for the irrigation of sodium-sensitive crops and exacerbates the risk of soil salinization. Based on the SAR and Na + % evaluation, the basin water was generally suitable for agricultural irrigation. Both non-carcinogenic health risks and carcinogenic risks were derived from As, and main source of its approach from the ingestion route. The CR value of As exceeded the safety threshold in China. Therefore, local governments should strengthen the regulation and control of As during the selection of drinking water sources.