Artificial environmental concentration coefficients of elements in soils in the Nanjing area

Abstract：Data of contents of relevant elements from“double-layer”soils have been obtained during multi-target geochemical survey in Nanjing and its surrounding areas. The ratio of the content of an element in topsoils (depth 10-20 cm) to its content in deep soils (depth 150-200 cm) is called artificial environmental concentration coefficient in soils. This paper mainly introduces the calculating methods of the artificial environmental concentration coefficients. According to the distribution characteristics of the concentration coefficients of various elements in the study area, it is found that in topsoils of the area the contents of elements such as Si, Ti, La, Ce, Y, Sc, Zr, Th , U and W are close to their contents in the natural soil environment and elements such as S, N, P, Hg, Pb, Cl, Br and Se, as well as Corg show pronounced artificial environmental concentrations, while elements such as I, Fe, Mg, Mn, Ca, Al and K are depleted in the topsoils. Finally, problems relating to an intensive study of the artificial environmental concentration coefficients of elements in topsoils are discussed and some helpful suggestions are put forward.