Source apportionment of and potential health risks posed by trace elements in agricultural soils: A case study of the Guanzhong Plain, northwest China.

A comprehensive study aimed at improving the understanding of trace elements (TEs) pollution of agricultural soils on Guanzhong Plain, northwest China, was performed. We apportioned the sources of TEs using various methods, and assessed the health risks for inhabitants by exposure to TEs. The results showed that the mean concentration of 9 TE A, Co, Cr, Cu, Mn, Ni, Pb, V, and Zn of 227 topsoil samples exceeded the background contents for the Guanzhong Plain but were lower than the relevant national soil quality standards. The total non-cancer risk values for adults and children were 4.3 and 9.5, respectively, and the total carcinogenic risks were 2.1 × 10 and 4.7 × 10, respectively. All these values were cause of the high health risk, and the results indicated that children were more susceptible than adults to environmental pollutants. Furthermore, Cr was the primary hazardous metal element to human health in agricultural soil, followed by Cu and As. Natural materials are the dominant sources of TEs to agricultural soil on the Guanzhong Plain, contributing 48% by mass of the total TE burden. Agricultural activities and traffic emissions contributed 29.4% and 22.6%, respectively, of the total TE burden. Even though natural source contributed most to the TE contents, anthropogenic sources contributed far more to the potential health risks posed to inhabitants of the study area. Our results show that health risk assessment in combination with TE source apportionment can serve as highly effective method in identification of primary harmfulness pollution source in the future.