Spatial distribution, health risk assessment and statistical source identification of the trace elements in surface...

Surface water samples were collected from the sampling sites throughout the Xiangjiang River for investigating spatial variation, risk assessment and source identification of the trace elements. The results indicated that the mean concentrations of the elements were under the permissible limits as prescribed by guidelines except arsenic (As). Based on the health risk indexes, the primary contributor to the chronic risks was arsenic (As), which was suggested to be the most important pollutant leading to non-carcinogenic and carcinogenic concerns. Individuals, who depend on surface water from the Xiangjiang River for potable and domestic use, might be subjected to the integrated health risks for exposure to the mixed trace elements. Children were more sensitive to the risks than the adults, and the oral intake was the primary exposure pathway. Besides, multivariate statistical analyses revealed that arsenic (As), cadmium (Cd), lead (Pb), selenium (Se), and mercury (Hg) mainly derived from the chemical industrial wastewaters and the coal burning, and zinc (Zn) copper (Cu) and chromium (Cr) mainly originated from the natural erosion, the mineral exploitation activities, and the non-point agricultural sources. As a whole, the upstream of the Xiangjiang River was explained as the high polluted region relatively.