中国城市土壤化学元素的背景值与基准值

Geochemical background and baseline value of chemical elements in urban soil in China

通过对中国31个省会城市3 799件表层土壤样品（0－20 cm）和1 011件深层土壤样品（150－180 cm）中52种化学元素（Ag、As、Au、B、Ba、Be、Bi、Br、Cd、Ce、Cl、Co、Cr、Cu、F、Ga、Ge、Hg、I、La、Li、Mn、Mo、N、Nb、Ni、P、Pb、Rb、S、Sb、Sc、Se、Sn、Sr、Th、Ti、Tl、U、V、W、Y、Zn、Zr、SiO2、Al2O3、TFe2O3、MgO、CaO、Na2O和K2O）及pH和有机碳（Corg）数据分布结构的研究，采用中位数绝对中位差法、正态和对数正态法计算出中国及31个省会城市土壤52种化学元素的地球化学背景值、基准值及它们的变化区间。数据显示，城市土壤中Corg、N、Ca、Hg、Ag、Au、Bi、Cd、Cu、Mo、Pb、S、Sb、Se、Sn、Zn元素的自然背景发生了显著变化，清晰显示出中国大规模的城镇化和工业化对这些元素在城市土壤中累积的重要贡献。这对全面认识中国城市土壤环境质量现状具有重要的现实意义，也是土壤环境质量保护立法及执法标准制定的重要依据。

Geochemical background and baseline values of 52 elements（Ag, As, Au, B, Ba, Be, Bi, Br, Cd, Ce, Cl, Co, Cr, Cu, F, Ga, Ge, Hg, I, La, Li, Mn, Mo, N, Nb, Ni, P, Pb, Rb, S, Sb, Sc, Se, Sn, Sr, Th, Ti, T1, U, V, W, Y, Zn, Zr, SiO2, A1203, TFe203, MgO, CaO, Na2O, and K2O）, pH and organic carbon and their ranges in urban soils at a national scale and in 31 provincial capital cities were calculated based on the data of 3799 topsoil samples and 1011 deepsoil samples, respectively, using an arithmetic for a normal data distribution, a geometric mean for a lognormal data distribution, and a median for neither a normal or a lognormal data distribution. Significant changes in geochemical backgrounds for Corg, N, Ca, Hg, Ag, Au, Bi, Cd, Cu, Mo, Pb, S, Sb, Se, Sn, and Zn were observed in urban soil, clearly indicating an important contribution from both the unexpected scale and pace of urbanization and industrialization to accumulation of chemical elements in urban soils. The urban soil geochemical background values of elements and their changes are very important both in recognizing the present state of urban soil environmental quality and establishing soil management legislation and law enforcement standards in China.